What Is Dlc In Road Construction? - [Answer] 2023: Stroymaster

10.01.2023

Introduction – In recent years, rigid pavements (portland cement concrete roads) are being constructed in many new projects due to added advantages of longer service life, smoother riding surface and little to no maintenance requirement. Government of India is encouraging the construction of cement concrete roads even at village and Municipal levels.

The current practices of the construction of cement concrete road for highways in India require a layer of dry lean concrete (DLC) as a base course over which pavement quality concrete slabs rest. It is one of the common and popular cement treated sub-base/base for concrete pavements. DLC is a no slump plain concrete with a large ratio of aggregate to cement.

It contains less amount of cement paste as compared to conventional concrete. DLC layer is an important part of modern rigid pavements. The major advantages of using DLC as base layer includes: provision of a uniform and strong support, high resistance to deformation, enhanced load transfer efficiency at joints, proper fixing of form work & proper placement of dowel bar cradles in semi mechanised construction, movement of construction equipments during construction of the roads, all weather construction and finally a reduction in the depth of pavement slab required from the point of view of axle load consideration etc.

Now a day, DLC is being also used during rehabilitation and strengthening of existing distressed bituminous roads with white topping. DLC is generally manufactured with ordinary Portland cement (OPC) as per IRC: SP-49: 1998 specification. The specification advocates use of other cement such as portland pozzolana cement (PPC), portland slag cement (PSC) also in the manufacture of DLC.

It sets a requirement of 10 MPa compressive strength of DLC at 7-day. The minimum ordinary portland cement (OPC) content of 150 kg/m3 is prescribed for it. But it does not give details such as cement content, aggregate to cement ratio, moisture content etc.

For DLC manufactured with PPC and PSC. Today, OPC is generally not readily available in open market even in megacity like Delhi. In small towns and cities dealers have to make full payment (1-2 months in advance) to get OPC from its manufacturers. As the supply of OPC in open market is highly restricted, the consumers have no option other than to use PPC.

The distinct differences between these two types of cement (PPC and OPC) include the presence of fly ash and much higher value of normal consistence of PPC. Table 1 presents some codal as well as generally encounter values of for the basic properties of OPC and PPC.

About 70% of cement produced in our country is PPC, therefore, the know-how and data generated through the research work will encourage use of correct amount of PPC in the manufacture of DLC.
For this purpose, an extensive experimental investigation was conducted to know the amount of PPC, the concrete mix proportions i.e.

aggregate to cement ratio and moisture content for the DLC to be manufactured with PPC so that the requirement of IRC: SP-49 specification in term of strength development could be met. This section of the article is only available for our subscribers. Kalyani Polymers is offering world-class made-in-India Synthetic Micro & Macro Concrete Fiber Products for the Construction Industry under the brand name FIBERCRETE®. Concrete is an integral part of any construction project, it can be roads, tall structures Read more, Leading cement and concrete maker ACC has unveiled a revolutionary thermal insulating climate control concrete system in India. Sridhar Balakrishnan, MD & CEO, ACC Limited, discusses its attributes, applications, and benefits for home builders, architects Read more, Dr. Manjunatha L R, Vice President – Direct Sales & Sustainability Initiatives, and Raghavendra, Senior officer, JSW Cement Limited, discuss bacterial concrete that can meet the requirements for strength, durability, and self-healing of cracks. Read more, Dada S. Patil, Assistant Professor, Civil Engineering Department, AIKTC, Panvel, Navi Mumbai, Maharashtra; Dr.S.B. Anadinni, Professor & Associate Dean (Core Branches), School of Engineering, Presidency University, Bengaluru; and Dr.A.V. Shivapur, Professor Read more, Samir Surlaker, Director, Assess Build Chem Private Limited, emphasizes the importance of a clear cover for a concrete structure since concrete as a porous material needs protection of its reinforcement. Along with the thickness (quantity) of cover, the porosity of Read more, Concrete technology has come a long way since the Romans discovered the material, with a number of ingredients, which include a host of mineral and chemical admixtures, besides of course, the Portland cement, aggregates (coarse and fine), and water. These ingredients Read more, Anil Kumar Pillai, GM, Ramco Cements, discusses two major softwares (Life 365 and DuraCrete), used in the industry for protection of RCC structures. The common design approach is faulty because we consider only the loading aspect, whereas the environmental aspect is equally Read more, Fibre Tuff, macro synthetic polypropylene fibres, are heavy-duty synthetic fibres that are specially engineered for use as secondary reinforcements, providing excellent resistance to the post cracking capacity of concrete. They are replacing steel fibres in a range Read more, Reinforced concrete design and construction practice has historically focused on the use of bonded straight or bend rebar as a method for rebar anchorage. This relies on bond integrity between the rebar and the concrete so that sufficient anchorage Read more, Innovation and entrepreneurship are essential ingredients in building a successful commercial venture. The ways in which these two concepts fuel enterprise are something entrepreneur’s never stop exploring. There is no doubt that innovation were Read more, Alite and belite are the predominant phases of Portland cement formulation. Alite is impure tricalcium silicate (C3S) and belite is impure dicalcium silicate (C2S). The impurities are an integral part as cement is manufactured Read more, Concrete is a versatile construction material and day by day its consumption is increasing globally. It is second only to water in the global consumption. No civil engineering structure is feasible without using concrete Read more, The use of Graphene with concrete has been talked about and researched ever since Graphene was invented in 2010 which grabbed its inventors a Nobel prize. Nanospan is the first company in the world to break technological and commercial Read more, Fosroc is the foundation of the JMH Group. It employs over 1700 employees in 17 operating companies based in Europe, the Gulf & Middle East, India, South Asia, and China. Through FGT, its trading company, it services another 50 countries Read more, Established in 1983 by French expatriate entrepreneurs, the Dextra Group has a long history of growth and development, driven by strong entrepreneurship and innovation. It has diversified into three main activities: manufacturing, trading and freight forwarding Read more, Jyotirmoy Mishra, Ph.D. Scholar, Department of Civil Engineering, Veer Surendra Sai University of Technology, Burla, Odisha, presents his research on the feasibility and compressive strength performance of geopolymer concrete Read more, As every one ton of Cement (OPC) produced, emits 0.96 tons of CO2, there is an urgent need to promote blending materials (ex. GGBS &PSC) and screened slag, to achieve lower CO2 emissions, reduce greenhouse gas effect, reduce exploitation Read more, In most of the developing countries, demand for steel for use as a reinforcing material is increasing day by day. However, when steel is in short supply, one can consider bamboo as an alternative material for reinforcement Read more, There is high demand for white cement in countries with hot climates, as more heat is reflected from white concrete surfaces as compared to standard grey concrete. As a value-added product, white cement is becoming Read more, Garry Martin, Director – Major Projects, Low & Bonar Construction Fibres, presents a new examination of the benefits of micro fibres in both the plastic and hardened state of concrete and their contribution to increased sustainability. Read more,

What is the grade of DLC?

Dry Lean Concrete (DLC) is an important part of modern rigid pavement. It is a plain concrete with a large ratio of aggregate to cement than conventional concrete and generally used as a base/sub base of rigid pavement.

What is DLC and PQC?

Using copper slag as ﬁne aggregate in pavement quality. concrete (PQC) and dry lean concrete (DLC) mixtures. DLC, which is popularly used for the construction of sub- base layer under concrete pavement in India, is a zero. slump concrete with maximum aggregate – cement ratio of.

What is the purpose of dry lean concrete?

Dry Lean Concrete: Everything You Need to Know About Dry Lean Concrete – Dry Lean Concrete is a mixture in which the amount of cement is less than the amount of liquid that is present in the layers. This makes it ideal as a base layer on which other types of concrete are placed on top.

It is good for a flat surface on uneven or dirty terrain. Concrete with high water content is considered thin because it has a lower cement concentration compared to other types of paving and building materials of this class. It is often used as a patch between bricks or other pieces of infrastructure to create a tight seal.

Dry Lean concrete bursts over time if it is not correctly applied or mixed according to the correct specifications. Careful preparation is the key to the success of dry lean concrete. Dry Lean Concrete is an important part of the modern rigid floor, It is smooth concrete with a large proportion of aggregate in relation to cement than conventional concrete and is generally used as a base/sub-base for hard paving.

The dry lean concrete is compacted using a 10 to 12T vibrating roller in the field.
Extra dry lean concrete is mainly done with ordinary Portland cement.
It consists of crushed sand, cement, and water.
The DLC is a sub-base for concrete pavement s; the minimum cement content in lean concrete must not be less than 150 kg/cum concrete (according to MORTH).

For DLC Cube Test, each cube must have an individual strength of 7.5mpa or more and an average of 5 cubes must have a force greater than 10mpa. The DLC plate must have an average thickness of 150 mm. Dry lean concrete is manufactured with ordinary Portland cement according to the IRC specification: SP-49: 199 8.

What is the density of DLC?

DLC Definition Diamond-like carbon (DLC) is a term which covers many new forms of carbon which have both graphitic and diamond like characteristics. The two images to the left show a couple of extreme cases; one being crystalline the other amorphous and smooth, each are 5×3 micrometers in size.

The top image is made by a chemical vapor deposition technique; the image is from a scanning electron microscope (SEM).
The lower image is made by PLD from a pyrolitic graphite target; the image is from an atomic force microscope (AFM).
DLC has many possible material properties as it becomes more diamond like and crystalline.

Its density is between graphite and diamond (2.2-3.5 grams/cubic centimeter). The optical properties are diamond like in index of refraction but a high extinction coefficient makes them dark. DLC is being used in the semiconductor industry and as a wear resistant coating.

What is CRM in road construction?

What is bitumen CRM? CRMB: Crumb Rubber Modified CRM is a mixture of and modified rubber is intrusive. The viscosity modifier rubber used asphalt binder and temperature resistance as well as resistance against brittle at low temperatures increases. CRMB has good adhesion to mineral mass, and thereby reduce brittleness and deformity.The advantages of CRMB:

The price is rightIncreased resistance to breakage increases the efficiency of asphalt on weather conditions and heavy traffic.Reducing road deformation at high temperaturesMore and return to the viscosity elastic than normalConstruction of the runway

Better adhesion propertiesStability and flexibilityUsers CRMB:Construction and repair of roads with high traffic : What is bitumen CRM?

What is the thickness of road?

Why thickness measurement in road construction is essential for the quality of the road In road construction, there is an infinite number of pinwheels to make the process as perfect as possible. Everything has to be considered and taken into account, starting with the planning, the tendering process, the specification of machines and staff, the choice of material and of course the paving process.

Looking at the process, I would like to go a little deeper into the different asphalt layers, because they have a significant impact on the resilience and many other characteristics that are often marginally mentioned.
The different asphalt layers and their tasks First, I would like to give a short introduction into the different layers and their functions.

Every layer is important for the reliability of the road. I. Base course The base course, as the name implies – along with the binder course – is the load carrying element of the road and gives the binder and top layer a consistent hold. Furthermore, the base course protects quickly and effectively from rainfall and other environmental conditions.

Exposed traffic forces are removed and evenly distributed on the base.
The layer thickness should be selected in such a way that the required compaction is achieved at each point of the street.
Often, with base course thicknesses of more than 15cm, the layer is paved in two production steps. II.
Binder course The binder course ensures that shear stresses are absorbed and thus deformations in the road are prevented.

Uneven surfaces remaining from the base course are further optimized in the binder installation, so that the perfect smoothness is achieved as soon as possible after the binder installation. The layer thicknesses stagger depending on the material and type of the road between 5cm – 12cm.

III. Top layer The top layer is the most heavily used layer of the road, because it is subject to the direct influence of traffic, weather and thawing agents.
Thus, the top layer must be particularly resistant to wear and deformation.
Durable evenness, grip, environmental friendliness and low noise are other properties required by the top layer.

In addition, the layer must be designed with structures, textures, colors and shapes. The specified layer thicknesses can be very different, depending on the requirement and the type of material. The classification of the road in its different asphalt layers and their components has an economic as well as a technical background.

Every single layer has its own special task as described above.
Its position, strength and material composition make it a part of the load-bearing capacity and resilience of the finished road.
The individual layers are combined into a compact structure in order to fulfill the desired specification, which is essential for the durability of the entire construction.

You might be interested: Dam Construction Is An Example Of Which Layout?

Not to be forgotten is the infrastructure aspect of every street, because the users of the road are also very interested in a stable road that meets the requirements. How do unstable or even too low layer thicknesses affect the overall road? 1. Lifetime of the road Unstable layer thicknesses prevent the individual layers from fulfilling their function.

F or example, if a road has changing thicknesses in the binder layer, it will absorb the resulting shear stresses better and worse.
Early road damage is the result.
However, if the binder course is made uniformly and consistently, the building structure will be evenly stressed and will be able to maintain its originally specified lifespan.

If there are irregular layer thicknesses in the top layer, premature road damage will be the result. Especially in the top layer you need to have a consistent layer thicknesses in order to avoid cracks or waves. If you are able to ha ve perfectl y leveled layers, stable thicknesses can much easier be achieved. It gets more critical if the layer thicknesses are irregular across all layers. Critical points over the entire course of the road are the result. There will be spots where the road will take early damage and not reach the desired lifespan. In the following sketch you can see, even as a layman, that something is wrong.

What is not critical in the base course, changes dramatically with the binder and even more in the top layer. If the binder course is irregular and even too thin in some places, it can no longer fulfill its task as a tension absorber. This problem gets even bigger in the base course, because in this case the problem becomes visible first.

Cracks and holes are the result of too thin and irregular layers. The durability of the road decreases significantly. 2. Economic and infrastructure aspects The economic aspect is especially important for the contractor because he has a great interest that the completed project achieves the quality to reach the specified and planned lifespan. The contractor will not have any warranty claims.

Especially contractors, but also road owners and we as the tax-payers are interested in roads with high quality and a long lifespan. One particularly essential basis for this are constant layer thicknesses, which are paved exactly as required. Furthermore, by working on the tolerance limits, the contractor gets the opportunity to save material and thus costs.

If one considers that with a material price of 80.00 EUR per ton, a paving scope of 100km with an average screed width of 6m can result in a saving of 80,000.00 EUR for every saving of 0.1cm layer thickness, the cost savings for a year can easily be calculated.

Even if the guidelines and specifications all over the world vary: At some point the road construction project and thus the paving material has to be paid.
At the end of the day, after each project, there are people using the street.
No matter if it´s on two-wheeled vehicles, cars, trucks or others.
Whether business or private purposes.

We all have a great interest in traveling safe and relaxed but still quick to reach our destination. : Why thickness measurement in road construction is essential for the quality of the road

Is code a CC road?

By Kaushal Kishore, Materials Engineer, Roorkee ABSTRACT: The stresses induced in concrete pavements are mainly flexural. Therefore flexural strength is more often specified than compressive strength in the design of concrete mixes for pavement construction.

A simple method of concrete mix design based on flexural strength for normal weight concrete mixes is described in the paper.
INTRODUCTION: Usual criterion for the strength of concrete in the building industry is the compressive strength, which is considered as a measure of quality concrete.
However, in pavement constructions, such as highway and airport runway, the flexural strength of concrete is considered more important, as the stresses induced in concrete pavements are mainly flexural.

Therefore, flexural strength is more often specified than compressive strength in the design of concrete mixes for pavement construction. It is not perfectly reliable to predict flexural strength from compressive strength. Further, various codes of the world specified that the paving concrete mixes should preferably be designed in the laboratory and controlled in the field on the basis of its flexural strength.

Therefore, there is a need to design concrete mixes based on flexural strength.
The type of aggregate can have a predominant effect, crushed rock aggregate resulting in concrete with higher flexural strength than uncrushed (gravel) aggregates for comparable mixes, assuming that sound materials are used.

The strength of cement influences the compressive and flexural strength of concrete i.e. with the same water-cement ratio, higher strength cement will produce concrete of higher compressive and flexural strength. Advertisements MIX DESIGN DETAILS IRC: 15-2011 specified that for concrete roads OPC should be used.

This code also allowed PPC as per IS: 1489 (Part-1) with flyash content not more than 20 percent by weight of PPC. Accordingly OPC + fly ash may be used in concrete roads. Flyash shall be not more than 20 percent by weight of cementitious material. However, IS: 456-2000 specified that fly ash conforming to grade-1 of IS” 3812 may be used as part replacement of OPC provided uniform blended with cement is essential.

The construction sites where batching plants are used this may be practicable. In ordinary sites where mixer or hand mixing are done uniform blending of fly ash with cement is not practicable. At such construction sites, PPC may be used. PPC should be used with caution where rapid construction methods like slip form is being used.

1	Characteristic Flexural Strength at 28 days	:	4.5 N/mm 2
2	Cement	:	Three mixes are to be designed
			MIX-A With PPC (Flyash 18 percent based) conforming to IS:1489-part-I-1991.7 days strength 37.5 N/mm 2, Specific Gravity : 3.00
			MIX-B With OPC-43- Grade conforming to IS: 8112-1989.7 days strength 40.5 n/mm 2, Specific Gravity : 3.15
			MIX-C With OPC of Mix-B and Fly ash conforming to IS:3812 (Part-I)-2003 Specific Gravity : 2.20
			Note: Requirements of all the three mixes are the same. Fine Aggregate, Coarse Aggregate and Retarder Super plasticizer are the same for all the three mixes.
3	Fly ash replacement	:	20% Fly ash is required to be replaced with the total cementitious materials.
4	Maximum nominal size of aggregates	:	31.5 mm Crushed aggregate
5	Fine aggregate and coarse aggregate grading	:	Given in Table 1
6	Minimum cement content for 4.5 N/mm2 characteristic flexural strength:	:	(a) OPC shall not be less than 360 kg/m 3, (b) PPC shall not be less than 425 kg/m 3, Fly ash in it 20% maximum by weight of total cementitious materials (c) OPC + Fly ash mix OPC shall not be less than 340 kg/m 3, Fly ash 20% maximum by weight of cementations material
7	Maximum free W/C Ratio	:	(a) For OPC 0.45 (b) For PPC 0.50
8	Workability	:	40 mm slump at pour the concrete will be transported from central batching plant through transit mixer, at a distance of 15 Km during June, July months. The average temperature last year during these months was 30 0 C.
9	Exposure condition	:	Moderate
10	Method of placing	:	Fully mechanised construction
11	Degree of supervision	:	Good
12	Maximum of cement content	:	(a) OPC 425 kg/m 3 (b) PPC 425 kg/m 3
13	Chemical admixture	:	Retarder Super plasticizer conforming to IS:9103-1999. With the given requirements and materials, the manufacturer of Retarder Super plasticizer recommends dosages of 1% bw of OPC, which will reduce 15% of water without loss of workability. For fly ash included cement dosages will be required to be adjusted by experience/ trials.2% maximum by weight of cementitious material
14	Values of Z x (for National Highway)	:	1.96 x 0.40

TEST DATA FOR MATERIALS AND OTHER DETAILS 1. The grading of fine aggregate, 1 & 2 aggregates are as given in Table.1.2. Properties of aggregates

Tests	Fine aggregate	Aggregate 1	Aggregate 2
Specific Gravity	2.65	2.65	2.65
Water Absorption %	0.8	0.5	0.5

3. Target average flexural strength for all A, B and C mixes S = S+ Zq =4.5 + 1.96 x 0.40 = 5.3 N/mm 2 at 28 days age 4. For Mix A, B and C free W/C ratio with crushed aggregate and required average flexural target strength of 5.3 N/mm 2 at 28 days from Fig.1 Curve D found to be 0.42.

This is lower than specified maximum W/C ratio value of 0.45 for OPC and 0.50 for PPC. Note: In absence of cement strength, but cement conforming to IS Codes, assume from Fig.1 Curve C and D for OPC 43 Grade Take curves C and D for PPC, as PPC is being manufactured in minimum of 43 Grade of strength.5.

Other data’s: The Mixes are to be designed on the basis of saturated and surface dry aggregates. At the time of concreting, moisture content of site aggregates are to be determine. If it carries surface moisture this is to be deducted from the mixing water and if it is dry add in mixing water the quantity of water required for absorption.

The weight of aggregates are also adjusted accordingly.
DESIGN OF MIX-A WITH PPC a) Free W/C ratio for the target flexural strength of 5.3 N/mm 2 as worked out is 0.42 for first trial.
B) Free water for 40 mm slump from Table 2 for 31.5 mm maximum size of aggregate.2/3×170 + 1/3×200= 180 kg/m 3 From trials it is found that Retarder Super plasticizer at a dosages of 1.3% bw of PPC may reduce 15% water without loss of workability Then water = 180 – (180 x 0.15) = 153 kg/m 3 c) PPC = 153/0.42 = 364 kg/m 3 (Required minimum PPC is 425 kg/m 3 ) d) Formula for calculation of fresh concrete weight in kg/m 3 U m = 10 x G a (100 – A) + C m (1 – G a /G c ) – W m (Ga – 1) Where, U m =Weight of fresh concrete kg/m3 G a =Weighted average specific gravity of combined fine and coarse aggregate bulk, SSD G c =Specific gravity of cement.

Determine actual value, in absence assume 3.15 for OPC and 3.00 for PPC (Fly ash based) A=Air content, percent. Assume for trial entrapped air 1.5% Advertisements For 31.5 mm maximum size of aggregate There is always entrapped air in concrete. Therefore ignoring entrapped air value as NIL will lead the calculation of higher value of density.

Take exact value of air as obtained in the test W m =Mixing water required in kg/m 3 C m =Cement required, kg/m 3 Note:- The exact density may be obtained by filling and fully compacting constant volume suitable metal container from the trial batches of calculated design mixes.
The mix be altered with the actual obtained density of the mix.

U m =10 x G a (100 – A) + C m (1 – G a /G c ) – W m (G a – 1) =10 x 2.65 (100 – 1.5) + 425(1- 2.65/3.00) – 153 (2.65 -1) =2409 kg/m 3 e) Aggregates = 2409 – 425 – 153 = 1831 kg/m 3 f) Fine aggregate = 1831 x 0.45 = 824 kg/m 3 Aggregate 1 = 1831 x 0.29 = 531 kg/m 3 Aggregate 2 = 1831 x 0.26 = 476 kg/m 3 g) Thus for 4.5 N/mm2 flexural strength quantity of materials per cu.m.

of concrete on the basis of saturated and surface dry aggregates: Water = 153 kg/m 3 PPC = 425 kg/m 3 Fine Aggregate (sand) = 824 kg/m 3 Aggregate (1) = 531 kg/m 3 Aggregate (2) = 476 kg/m 3 Retarder Super Plasticizer 1.3% bw of PPC = 5.525 kg/m 3 MIX- B WITH OPC a) Water = 180 – (180 x 0.15) = 153 kg/m 3 b) OPC = 153/0.42 = 364 kg/m 3 c) Density: 10 x 2.65 (100 – 1.5) + 364 (1 – 2.65/3.15) – 153 (2.65 – 1)= 2416 kg/m 3 d) Total Aggregates = 2416 – 364 – 153 = 1899 kg/m 3 Aggregate 1 = 1899 x 0.29 = 551 kg/m 3 Aggregate 2 = 1899 x 0.26 = 494 kg/m 3 Fine Aggregate = 1899 x 0.45 = 854 kg/m 3 e) Thus for 4.5 N/mm 2 flexural strength quantity of materials per cu.m of concrete on the basis of SSD aggregates are given below: Water = 153 kg/m 3 OPC = 364 kg/m 3 Fine Aggregate (sand) = 854 kg/m 3 Aggregate (1) = 551 kg/m 3 Aggregate (2) = 494 kg/m 3 Retarder Super Plasticizer 1% bw OPC = 3.640 kg/m3 MIX-C WITH OPC + FLY ASH With a total cementitious material of 430 kg/m 3, OPC = 430 x 0.80 = 344 kg/m 3 Fly ash = 430 x 0.20 = 86 kg/m 3 Mix on the basis of SSD Aggregates, (1) Water as worked out earlier = 153 kg/m 3 (2) OPC = 344 kg/m 3 (3) Fly ash = 86 kg/m3 Density = 10 x 2.65 (100 – 1.5) + 430 (1 – 2.65/3.00) – 153 (2.65 – 1) = 2410 kg/m 3 Total Aggregates = 2410 – 153 – 344 – 86 = 1827 kg/m 3 (4) Fine aggregate 0.45 x 1827 = 822 kg/m 3 (5) Aggregate (1) 0.29 x 1827 = 530 kg/m 3 (6) Aggregate (2) 0.26 x 1827 = 475 kg/m 3 (7) Retarder super plasticizer 1.5% bw of cementitious material = 6.450 kg/m 3 Note: (1) Cementitious material worked out as per IRC : 15-2011, which specified: In case fly ash (as per IS: 3912 Part 1) is blended at site, the quantity of fly ash shall be restricted to 20 percent by weight of cementitious material and the quantity of OPC in such a blend shall not be less than 340 kg/m 3,

(2) After the first trial mix, its actual density is to be determined, as specified elase where in this paper. The mix proportions shall then be worked out accordingly including the water content, the dosages of Retarder SP for required workability keeping the free w/c ratio with in the permissible limits and adjusting it according to the required flexural strength.

Materials	MIX. ‘A’ with PPC	Mix. ‘B’ with OPC	Mix. ‘C’ with OPC+Flyash
Water kg/m 3	153	153	153
PPC kg/m 3	425	—	—
OPC kg/m 3	—	364	344
Flyash kg/m 3	—	—	86
Fine Agg. kg/m 3	824	854	822
Agg. (1) kg/m 3	531	551	530
Agg. (2) kg/m 3	476	494	475
Retarder Super- plasticizer kg/m 3	5.525	3.640	6.450
W/ Cementitious ratio	0.36	0.42	0.356

Note:- 1. For exact W/C ratio the water in admixture should also be taken into account.2. PPC reduces 5% water demand. If this is found by trial then take reduce water for calculation.3. If the trial mixes does not gives the required properties of the mix, it is then required to be altered accordingly.

However, when the experiences grows with the particular set of materials and site conditions very few trials will be required, and a expert of such site very rarely will be required a 2nd trial. CONCLUSION 1. For 4.5 N/mm 2 flexural strength concrete having same material and requirement, but without water reducer, the OPC required will be 180/0.42 = 429 kg/m 3 2.

With the use of superplasticizer the saving in OPC is 65 kg/m 3 and water 27 lit/m 3,3. In the financial year 2009-2010 India has produces 200 million tonnes of cement. In India one kg of cement produce emitted 0.93 kg of CO 2, Thus the production of 200 million tonnes of cement had emitted 200 x 0.93 = 186 million tonnes of CO 2 to the atmosphere.4.

If 50 million tonnes cement in making concrete uses Water Reducers 7500000 tonnes of cement can be saved.3750000 KL of potable water will be saved and the saving of Rs.3300 crores per year to the construction Industry.6975000 tonnes of CO 2 will be prevented to be emitted to the atmosphere.
The benefits in the uses of water reducers not limited to this.

You might be interested: How Do You Measure A Roof For Shingles?

When water reduces shrinkage and porosity of concrete are reduces which provides the durability to concrete structures.5. India is facing serious air, water, soil, food and noise pollution problems. Every efforts therefore are necessary to prevent pollution on top priority basis.6.

As the stress induced in concrete pavements are mainly flexural, it is desirable that their design is based on the flexural strength of concrete.
The quality of concrete is normally assessed by measuring its compressive strength.
For pavings, however, it is the flexural strength rather than the compression strength of concrete which determine the degree of cracking and thus the performance of road, and it is imperative to control the quality on the basis of flexural strength.7.

As per IRC: 15-2011, in case of small size projects, where facilities for testing beams with three print loading are not available, in such cases, the mix design may be carried out by using compressive strength values and there after flexural strength will be determined as per correlation between flexural strength with compressive strength given the following equation.

1	IS : 383-1970	Specifications for coarse and fine aggregates from natural sources for concrete (second revision) BIS, New Delhi
2	IS: 456-2000	Code of practice for plain and reinforced concrete (fourth revision), BIS, New Delhi
3	IS: 9103-1999	Specification for admixtures for concrete (first revision) BIS, New Delhi
4	IS: 8112-1989	Specifications for 43 Grade ordinary portland cement (first revision) BIS, New Delhi
5	IS: 2386 (Part-III) 1963	method of test for aggregate for concrete. Specific gravity, density, voids, absorption and bulking, BIS, New Delhi
6	IS: 3812 (Part-I) 2003	Specification for pulverized fuel ash: Part-I for use as pozzolana in cement, cement mortar and concrete (second revision) BIS, New Delhi
7	IS: 1489-Part-I 1991	Specifications for portland pozzolana cement (Part-I) Flyash based. (Third revision), BIS, New Delhi
8	IRC: 15-2011 – Standard specifications and code of practice for construction of concrete road (Fourth revision)
9	Kishore Kaushal, “Concrete Mix Design Based on Flexural strength for Air-Entrained Concrete”, Proceeding of 13 th Conference on our World in Concrete and Structures, 25-26, August, 1988, Singapore.
10	Kishore Kaushal, “Method of Concrete Mix Design Based on Flexural Strength”, Proceeding of the International Conference on Road and Road Transport Problems ICORT, 12-15 December, 1988, New Delhi, pp.296-305.
11	Kishore Kaushal, “Mix Design Based on Flexural Strength of Air-Entrained Concrete”. The Indian Concrete Journal, February, 1989, pp.93-97.
12	Kishore Kaushal, “Concrete Mix Design Containing Chemical Admixtures”, Journal of the National Building Organization, April, 1990, pp.1-12.
13	Kishore Kaushal, “Concrete Mix Design for Road Bridges”, INDIAN HIGHWAYS, Vol.19, No.11, November, 1991, pp.31-37
14	Kishore Kaushal, ” Mix Design for Pumped Concrete”, Journal of Central Board of Irrigation and Power, Vol.49, No.2, April, 1992, pp.81-92
15	Kishore Kaushal, “Concrete Mix Design with Fly Ash”, Indian Construction, January, 1995, pp.16-17
16	Kishore Kaushal, “High-Strength Concrete”, Bulletin of Indian Concrete Institute No.51, April-June, 1995, pp.29-31
17	Kishore Kaushal, “Concrete Mix Design Simplified”, Indian Concrete Institute Bulletin No.56, July-September, 1996, pp.25-30.
18	Kishore Kaushal, “Concrete Mix Design with Fly Ash & Superplasticizer”, ICI Bulletin No.59, April-June 1997, pp.29-30
19	Kishore Kaushal. “Mix Design for Pumped Concrete”, CE & CR October, 2006, pp.44-50.

Table.1: Grading of Aggregates

IS Sieve Designation	Percentage of passing by mass
Fine aggregate from river 45%	Crushed aggregate	Combined grading of mix	IRC: 15-2011 recommended grading of combined aggregates for pavement quality concrete (PQC)
(1) 29%	(2) 26%
31.50 mm	100	100	100	100	100
26.50 mm	100	100	98	99	85 – 95
19.0 mm	100	100	25	81	68 – 88
9.50 mm	100	46	0	58	45 – 65
4.75 mm	94	5		44	30 – 55
600 micron	42	0		19	8 – 30
150 micron	10			5	5 – 15
75 micron	2			1	0 – 5

Table.2: Approximate free-water content (kg/m3) required to give various levels of workability for non-air-entrained (with normal entrapped air) concrete.

Maximum size of aggregate (mm)	Type of aggregate	Slump (mm)	25 + 10	40 + 1031.5
	Uncrushed Crushed		160 190	170 200

Note:- When coarse and fine aggregate of different types are used, the free water content is estimated by the expression.2/3W f +1/3W c Where, W fsub>= Free water content appropriate to type of fine Aggregate And W c = Free water content appropriate to type of coarse aggregate. We at engineeringcivil.com are thankful to Er. Kaushal Kishore for submitting the revised mix design as per IRC:15-2011. This will be of great help to all civil engineering students and faculty who are seeking information on mix design based on revised IRC.

Why PCC is used in foundation?

The objective of plain cement concrete alias PCC is to arrange a firm impermeable bed to RCC in the foundation where the soil is soft and flexible. It is mostly applied over brick flat soling or devoid of brick flat soling. It is also known as Cement Concrete (CC) or Blinding Concrete.

When, any reinforcement is not used inside the concrete, it is defined as the plain cement concrete. It’s just a blend of concrete ingredients. Characteristics of Plain Cement Concrete – Given below, some vital characteristics of plain cement concrete: • Compressive strength: 200 to 500 kilogram/square centimeter • Tensile strength: 50 to 100 kilogram/square centimeter • Density: 2200 to 2500 kilogram/cubic meter • Stability: Outstanding Applications of Plain Cement Concrete: PCC is mostly found in footings, grade slabs, and concrete roads.

When the underlying soil is weak and flexible, brick flat soling is provided under PCC. To form PCC, the following materials are utilized :- Cement: Normally, the Portland cement is utilized as bonding material in PCC. Fine Aggregate: Sand is employed as fine aggregate.

The fineness modulus (FM) of sand should remain 1.2 to 1.5.
FM stands for an index number that demonstrates the mean size of particles in sand.
It is measured by carrying out sieve analysis.
Coarse Aggregate: Usually, the brick chips are utilized for developing PCC.
It is also possible to utilize stone chips in these conditions.

The size of the coarse aggregate remains 20mm downgrade. Water: Pure drinkable water should be provided in PCC. How to build up PPC? With the following methods, plain cement concrete is formed. The following tools are utilized for the production of PCC • Wooden or Steel rammer • Mixture machine (if any) The Thickness of PCC: The thickness of PCC is normally 50mm over Brick Flat Soling (BFS).

If you don’t use BFS below PCC then the thickness should be 75¬mm. When the PCC is used in car parking area then the thickness should be 75mmover BFS. Ration of materials in PCC: The ratio of cement, sand and brick chips in foundation or basement should be 1:3:6. But, if it is applied in the car parking area, the ratio will be changed to 1:2:4.

The production method for PCC: If ready-mix concrete is applied, this step should be omitted. If PCC is produced through mixture machine then click ” How to mix concrete by mixture machine “. If the concrete is mixed manually, get help by clicking on this link ” how to mix concrete by hand “.

Placing and Compaction of PCC: • Ensure that brick soling/sand bed level is perfect for PCC. • Create formwork for PCC with wooden planks according to stipulated dimensions. • There should be no dust and foreign materials in concreting area. • The bed of PCC should be covered with polythene. • Create level pillars of fresh concrete in the area at proper spacing but not in excess of 2m c/c both ways.

• Set the concrete softly from one side. Apply the mixed concrete within 45 minutes once the water is added. • For compaction and finishing of PCC, wooden rammer should be used. • The surface of PCC should be rough to combine future work prior to solidification of the concrete.

What is the ratio of PQC?

A control mix for PQC was prepared with 400 kg/m 3 of ordinary Portland cement (OPC) and water–cement (w–c) ratio of 0.40. Other concrete mixtures were then prepared by substituting 20%, 40%, 60%, 80% and 100% copper slag in control mix.

What is the thickness of dry lean concrete?

22.12.3 Specimen calculation of foundation – According to the architect’s specifications, the foundations have been used in bearing the concrete slab floor. The foundation dimensions are shown in Figure 22.8, The different foundation material components are as follows: Figure 22.8, Cross-section of foundation. • Lean concrete : Its role is to provide the uniform surface to the foundation concrete and to prevent the direct contact of foundation concrete with the soil. Its thickness is 5 cm. It is mixed at 150 kg/m 3, • Concrete for ground beam, column footings: This is mixed at 350 kg/m 3,

How much does DLC cost?

What Is DLC? – DLC can come in many flavors and types, and is often discussed in different terms depending on the nature of the content and the platform. In-app purchases are often DLC, but not always. DLC can be skins, maps, characters, weapons, scenarios, game modes or even entirely new games built using the same game engine.

Adding to the complexity is the fact that DLC can be found in many different sizes, from a relatively small piece of art to a complex, multi-gigabyte game mode or entirely new game built on the core game’s engine. DLC can be cheap, fast and easy to develop in terms of production, or it can be an enormous effort that can take more than a year.

With the variation in development cost and time, it follows that DLC can be priced anywhere from free to $20 or more. There are certain patterns to DLC and what can be found in games, and this is normally similar within games of a particular genre on a particular platform.

Console first-person-shooters for instance, tend to have DLC that is centered around new maps, and often priced at around $10 or $15 for a set of maps (often bundled with a new character class, weapons, scenarios, or even a new game mode). Console games have fallen into a pattern of announcing DLC plans with the launch of the game, and offering a “season pass” to all of the game’s DLC for the next year, usually at a discount.

A typical offering might be a $60 core game and then four $15 DLC releases over the next year, with a season pass discounted to $40 or $50. PC games follow different patterns. World of Warcraft, for instance, has been delivering major expansion packs (the term they use for their DLC) about every 18 months or so, which is not unreasonable given the huge amount of work that goes into each one.

The next expansion, Legion, is $49.99, and there’s a Collector’s Edition for $89.99 as well. Both include new areas, a new character class, and many changes to the game. When you look at games like League of Legends though, you’ll find many inexpensive skins (collections of art and animation) to buy for prices ranging from a few dollars to nearly $25, while champions can be had for less than $7 for the most part.

Mobile games often have continually added new content, as well as content that can be purchased within the game. Often the major game purchases for mobile games are not content per se, but added game time.

Do you have to pay for DLC?

What is DLC? Downloadable content, or DLC, is what gamers call extra content players can download after purchasing a video game. While some DLC is offered for free, players typically must pay additional fees to unlock new content. Freemium games rely entirely on DLC to make a profit.

Does DLC cost money?

The different types of DLC – There are different kinds of DLC available for all types of games. Some of them affect gameplay and take up a lot of space on your console, while others are hardly noticeable. DLC can include extra stories and levels, new characters, unlockable weapons, bonus items, and more depending on the type of game. An example of downloadable content — in this case, new character outfits — for Nintendo’s “Super Smash Bros Ultimate.” Nintendo; Sora Ltd. Some games offer DLC for free, which you can download from your console’s online gaming store. However, it’s much more common for companies to charge for DLC, especially if it adds a significant amount of content.

Games that have a lot of DLC released over time may offer a package deal called a “season pass.” Season passes include all current and future DLC for a given game, usually at a discounted price, so you only need to pay for the game’s DLC once even if some of it hasn’t been released yet.
Chrissy Montelli is a writer and content creator originally from Long Island, NY.

She is the author of two poetry chapbooks, Heart Float (Bottlecap Press) and Going to Ithaca (Ghost City Press), as well as various online publications. Read more from her at chrissymontelli.wordpress.com, Read more Read less

What is the mix ratio of m30 concrete?

He modiied ratio was arrived as 1:2.23:2.12 with water-cement ratio of 0.38.

How is Wmm prepared?

Wet Mix Macadam consist of laying spreading and compacting of clean, crushed, well-graded granular materials on a prepared and approved Granular sub-Base. The material is well mixed with water and rolled to a dense mass. It shall be laid on one or more layers as per line and level, grade and cross section shown in the drawing or as directed by the Engineer.

The thickness of single compacted Wet Mixed Macadam (WMM) Base shall not be less than 75 mm.
Maximum thickness of single compacted layer base can be up to 250 mm upon approval of Engineer.1.
Reference 2.
Setting Out.3.
Selection of Material.4.
Equipments.5.
Methods of Operation.6.
Quality Control.7.
Work Safety.8.

Environmental Safety.1.0 Reference Reference Documents:- I) Ministry of Road Transport& Highways Specifications II) Technical Specifications III) Relevant Drawings. IV) IS 2720 Codes.2.0 Setting Out After the layer of GSB Sub-Base has been approved, then line and level are carried out to fix the Wet Mix Macadam base layer (herein after called WMM Base).

Pegs are fixed at regular intervals on the safe side of the road edge where blade of grader should not disturb the peg while blending of the Base materials.
On each peg’s top level of Base layer is marked.
The chainage boards and working bench mark shall be set out side the limits of construction areas.3.0 Selection of Material 3.1 Aggregate Coarse aggregate shall be crushed stone or crusher run as per IRC 109 or clause 406.2.1 of MORT&H specification.3.2 Physical requirement The constituents of the aggregates shall be produced by integrated crushing and screening plant (Impact or Cone type) and, unless otherwise instructed by the Engineer, crushing shall be carried out in at least two stages.

You might be interested: What Is The Crushing Strength Of First Class Brick?

The fraction of material passing through 4.75mm sieve shall also be crusher run screening only. The aggregate shall conform to the physical requirements set forth in Table 400-12 of MORT&H. or IRC 109 clause 3.1.1 If the water absorption value test of coarse aggregate is greater than 2 per cent, the soundness test shall be carried out on the materials delivered to site.3.3 Grading Requirement The aggregate shall conform to the grading given in table 406.2.1.2 of technical specification or IRC 109 -2015.

Material finer than 425 micron, shall have Plasticity Index (PI) less than 6.
The final gradation approved within these limits shall be well graded from coarse to fine and shall not vary from low limit on one sieve to high limit of adjacent sieve or vice versa.4.0 Equipments The following equipments shall be carried out for the WMM 1.

Wet Mix Macadam Plant 2. Dumper / Tippers.3. Vibro Roller (80 to 100 KN) 4. Water Tanker 5. Paver capable of paving more than 9 meter width.6. Survey kit / instrument 5.0 Method of Operation 5.1 Preparation of WMM Base (As per clause 406.3.1): 5.1.a Provision of lateral confinement of aggregates Proper arrangement shall be made for the lateral confinement of wet mix during laying.

This shall be done by laying materials on adjoining shoulder along with that of WMM layer.
The preparation of mix, spreading of mix and compaction are done sequentially.
The sequence of operation shall be followed as described in clause: 406.3.3 of MORT&H.5.2 Preparation of mix Wet mix Macadam shall be prepared in an approved WMM mixing plant having provision for controlled addition of water and forced/positive mixing arrangement.

Optimum moisture for mixing shall be determined in accordance with IS: 2720 (Part 8) after replacing the aggregate fraction retained on 22.4 mm sieve with materials of passing from 22.4 and retained on 4.75 mm. While adding water, evaporation loss shall also be taken into account.

The mixed material should be uniformly wet and no segregation shall be permitted.5.3 Spreading of mix Immediately after mixing, the aggregate shall be spread uniformly and evenly upon the approved GSB layer. Materials should neither be dumped in heap nor their hauling over a partly completed stretch.

The first layer will be laid by motor grader and the second layer mix shall be spread by a WMM paver finisher capable of paving minimum 4.5m to 9.0m width. The layer may be tested by depth block during construction. No segregation of materials are allowed.

The aggregates should be of uniform gradation with no pockets of fine materials.5.4 Compaction After the mix has been laid on site to the required thickness, grade and camber, then compaction is carried out with suitable roller to the full depth.
For a thickness up to 200mm in a single layer, compaction shall be done with vibratory roller of 80 to 100 KN static weights with plain drum or equivalent capacity roller.

Rolling is done from lower edge towards upper edge longitudinally for the portion having unidirectional cross fall and super elevation. Each pass of the roller shall uniformly overlap not less than one third of the track made in the previous pass. During rolling, grade and cross fall shall be checked and any high spot or depressions, which become apparent, corrected by adding or removing fresh materials.

The speed of roller shall not exceed 5km/h. Rolling shall be continued till the density of the layer is achieved 98% of the Maximum Dry Density. Rolling should not be done when the WMM layer is soft or yielding or when it causes a wave like motion. If level difference or irregularities develop during rolling which exceeds 12 mm when tested with 3 metre straight edge, the surface should be loosened and premixed materials added or removed as required before rolling again.

In no case the unmixed material be permitted to make up the depressions.5.5 Opening to traffic After testing the compaction & level of WMM course the road shall be allowed to dry for 24 hours. Preferably no vehicular traffic should be allowed on the finished WMM surface till it has dried and covered with wearing course.6.0 Quality Control Table 400-12 Physical Requirement of coarse aggregate for Wet Mix Macadam for Sub-base /Base Courses 406 WET MIX MACADAM SUB BASE /BASE Table 400- 13: Grading Requirement of Aggregate for Wet Mix Macadam

Control Tests for Granular WMM Base: Post Construction Tolerance in Surface Level : +10 mm permissible undulation (with 3 m straight edge) : 8 mm no. of undulations permitted in any 300 m length, exceeding 12 mm: 20 Control on quality of materials and works shall be in accordance to section 900 of MORT&H.

7.0 Work Safety 1.Safety will be provided location specific safety plan.8.0 Environmental Safety 1.Nearby Streams, water courses, lakes, reservoir shall be protected from contamination by the soil erosion from areas exposed during excavation by constructing temporary berms, dykes, sediment Basins, slopes, drains & by the use of temporary mulches, seeding or other control devices.2.Vehicles tracks shall be kept moist to prevent flying of dust particles with the vehicle movement.

What are the 3 types of CRM?

Examples of operational CRM systems –

Mailchimp positions its platform as marketing CRM software for small businesses. The system aims to help organizations get to know their audience through their platform and find new ways to market them. HubSpot combines its marketing, sales, service and CMS hubs into, a platform to align internal teams, pull meaningful insights and report on growth opportunities. Furthermore, HubSpot has integrations to facilitate marketing, sales and service processes.

The three types of CRM systems are operational, analytical and collaborative. The primary goal of analytical CRM is to leverage customer data into trends and actionable insights the organization can use to improve the customer experience. Data from an analytical CRM can include customer preferences, channels, touchpoints, trends, forecasting and more.

What are the 2 types of CRM?

There are three main types of CRM systems: collaborative, analytical, and operational.

What is the grade of PQC?

PQC stands for Pavement Quality Concrete (PQC) Grade of PQC is Generally M40 and it is designed as per IRC:15-2002. PQC is used for the construction of Concrete roads as a top wearing layer. The thickness range generally starts from 180mm up to 300 mm.

What is the meaning of DLC concrete?