1. How to calculate the expiry date of cement bags? – Every bag of cement has manufactured dates printed over them as shown below. As you can see in the above image, the manufactured date of cement is printed as W48 DEC Y13. Here, W stands for 👉 Week. DEC stands for 👉 Month, Y stands for 👉 Year. W48 DEC Y13 means, the cement is manufactured on the 48th week of the year 2013 in the month of December.
- By observing the calendar (internet ), the 48th week is from Nov 25th to Dec1st of the year 2013.
- We should add 3 months ( 90 days ) to the manufactured date, to get the expiry date of cement.1st Dec 2013 + 90 days.
- = 28th February 2014 will be the expiry date of cement.
- So, it is OK to buy this bag of cement before 28th Feb of the year2014,
The other pattern of printing the manufactured date over the cement bags is as below. As explained above, W, M, & Y stands for a week, month & year respectively. Now the next question that comes to your mind is,
- 1 How do you read a cement date?
- 2 How much old cement can be used as per IS code?
- 3 How can we check the quality of cement?
- 4 What does 42.5 mean in cement?
- 5 How long does unopened cement last?
How long does cement take to expire?
The shelf life of cement is 3 months – When cement comes in contact of moisture, it undergoes a process called Hydration. This makes it crucial to protect cement from moisture even within the 3 month period. This is why it is important to store cement carefully and prevent it from coming in contact with moisture. Below are points to keep in mind when storing cement –
1.Keep cement in dry, leak-proof and moisture-proof environment.2.Doors and windows must be kept closed.3. Bags must be stacked on a wooden plank or on a strong tarpaulin at 6 inch above the ground.
How do you read a cement date?
Which Cement is Best for House Construction? UltraTech March 25, 2019 The process of building a home typically includes many stages and in most of these stages, your choice of cement will play a crucial role. There are three main types of cement for constructing a home – OPC, PPC and PSC.
- Among the three, you will find OPC is available almost everywhere, but PPC and will give better strength and excellent durability.
- Before purchasing the cement, make sure to check the manufacturing date.
- If the cement bag is older than 90 days, you should consult your engineer.
- You will find the manufacturing date, along with other important details like the MRP and the ISI stamp, printed on the side of the bag.
Make sure to inspect the cement bag for lumps as this makes the cement unsuitable for construction. In trying to pick the right cement, don’t be influenced by price alone. In an attempt to bargain and save money in the short-run, you risk paying a big price in the long-run.
How much old cement can be used as per IS code?
Cement storage – usage & guidelines as per the CODAL provisions There are doubts in the minds of construction professionals regarding storage of cement, duration of storage, cement storage guidelines and recommendations on ways to evaluate storage of cement and its usage.
- This subject is not new as many construction professionals are aware of it and there are inputs through much academic literature on the subject, Bureau of Indian Standard codes and experts’ views.
- Concrete is used for its compressive strength.
- If cement does not hydrate on exposure to moisture or water the very purpose of usage of cement in concrete is defeated as it is through reaction of cement and water which is known as hydration through which concrete gains compressive strength,A.
We are emphasizing few clarifications on the subject, already known to construction professionals in this write up,
Cement storage Cement can be stored for upto 3 months before usage as per codal provisions. As per codal provisions, cement stored beyond 3 months can also be used but it need to be retested before use and shall be rejected if it fails to confirm to any standards If the cement is stored properly and cement has not been exposed to moisture or dampness, one can confidently use the cement for the works. Guarantee of cement quality The Cement manufacturer can guarantee the quality of cement, which is stored as per standard guidelines mentioned by Bureau of Indian Standards. Inspection of bags on storage If there are lumps, which could be broken by hands, it clearly indicates that the storage of cement is in the open, moisture or dampness would have affected the quality of cement and that would have led to partial lumps. If hands can break the lumps the cement can be used. This is because cement has not reacted with water and hence no hydration has taken place. However if the bags are fully clotted or granulated this could be because of exposure of either moisture or water with cement as cement is hygroscopic. This hygroscopic nature of cement is an indication of its affinity to water which leads to hydration of cement thereby leading to hard lumps in cement bags or in extreme cases the full bag is hardened and cake like phenomenon is seen. If lumps are soft and breakable the cement can be used. If hard, the lumps may be removed by screening and the reclaimed cement sent for testing. Testing stored cement If there is suspicion on the quality of cement after prolonged storage then either the cement can be tested or one can adopt a practical site trial of casting concrete cubes using the standard recommended proportions and check the concrete compressive strength of cubes for the desired period – 1 day, 3 days or 7 days.
B. Cement storage guidelines as per IS 4082 IS 4082-1996 laid down the stipulation for storage of cement as follows:
The height of stack shall not be more than 10 bags to prevent the possibility of lumping up under pressure.Do not store cement in the open. Under exceptional conditions, cement can be stored on a raised damp proof floor and covered with tarpaulins on the top and sides. Ensure that rain water does not stagnate on the tarpaulin. Storage in the open should be limited to the minimum possible time i.e. about 48 hours.On building contracts, lower stories and other completed portions of buildings may be used for cement storage. In such cases cement should be protected from rain that may blow in through the openings. Also protect cement from water dripping from curing or other operations in the upper floors.Normally store cement in weatherproof sheds.The floor in the shed should be dry and raised at least 150 mm from ground level.Place the bags tightly together to avoid air circulation.
C. Method of testing Cement for freshness as per IS code Loss on Ignition test is a cement test recommended as the codal provisions to evaluate the freshness of cement which helps us to understand if the cement is adulterated with moisture or any other impurities.
Here 1 gram of cement sample is heated to a temperature between 900 to 1000 C and the loss in weight is measured. Owing to the presence of sulphide in slag cements which may be oxidised to sulphates, there may be a gain instead of loss in some cases and this should be reported. As per the respective codes, for OPC 53 grade, the Loss on ignition value must not exceed 4%, whereas for PPC, PSC, SRC and Rapid hardening Portland cement it must not exceed 5% All the above guidelines have been outlined in the respective codes for so many years.
The responsibility of proper storage of cement therefore lies with the user. Issued by Institutional Organisation with inputs from Ramco Cements Ltd. : Cement storage – usage & guidelines as per the CODAL provisions
What date is expiry date?
What is an “expiration date” and how is it different? – Some foods – such as meal replacements, nutritional supplements, infant formulas and formulated liquid diets – must carry an expiration date. The expiration date is the date up to which the food maintains its microbiological and physical stability and the nutrient content declared on the label.
When did expiry date start?
Today’s blog post was written by High Tech Middle Media Arts 6th grader, Kaiya. Kaiya’s class studied the impact that humans have on our local water resources and their contribution to food waste on a global scale. The students looked into water and food waste issues locally, statewide, nationwide and globally. Illustration by John Wagner Have you ever wondered how expiration dates work? Wondered how important they are? Well, I certainly did. So to those who still do, let me explain. Let’s start with a short history lesson. Expiration dates were introduced in 1950 at a store called Marks & Spencers.
- It wasn’t until 1970 when “Sell By” and “Best By” tags were added to most supermarkets.
- Now that our history lesson has concluded, let’s get to the interesting stuff! Expiration dates aren’t supposed to show a fruit’s edibility, but the fruit’s “peak quality”; not when it’s expired.
- It’s because of this common misconception that people discard perfectly good food! So actually, expiration dates are optional.
They are suggestions meant to assist. It’s more important to know your food and to simply throw it out because of the expiration date. Oftentimes, grocery stores will throw away their produce once it turns brown.
Can old cement be reused?
RECYCLED CONCRETE USES – Old, unneeded concrete can be recycled and used to create recycled aggregate. In most cases, recycled aggregate will be used as a subbase material, but it can also be paired with virgin materials and reused as an aggregate in new concrete.
CA6 recycled PCC and Grade 8 recycled are common aggregates made from recycled concrete. They are commonly used as a base for roads, parking lots, and driveways, as well as backfill material and shoulder stone. Recycled concrete can also be used to create 2″-4″ recycled stone. This product is typically used for site stabilization, bottom layer road base, and backfill.
Besides stone, recycled concrete can also be used to create engineered fill sand. This fine-grained material neutralizes pH levels and is commonly used for environmental fill and remediation projects.
How can we check the quality of cement?
Skip to content Home / blog / How to Check the Quality of Cement When you are putting all your blood, sweat and tears into your construction project, you want to make sure that you are working with the best material you can find. It is crucial for every builder and contractor to check the quality of the cement being used on the site during the time of preliminary inspection.
- If good cement is not used, then the quality of the entire construction is at stake.
- The overall strength of your structure depends on many factors, and the quality of cement you are using is one of them.
- Excellent quality cement should always be used to achieve desired strength of concrete and to make sure the structure stands tall for a long time.
So, how does one check the quality of cement being used? Following are some easy tests to be used.1) Date of Packing – Unlike wine, the strength of cement being used decreases with time. Cement should be used before 90 days from the date of manufacture.
A year after manufacture, the strength of the cement is reduced by 40-50%.2) Colour of Cement – Good cement is always uniform in colour. You can identify good cement by its gray colour with a slight green shade.3) Lumps – In cement, lumps are formed due to absorption of moisture. Good cement has no lumps.4) Temperature – If you push your hand inside a bag of good cement, you should feel a certain coolness.
Bad cement feels warm in your hand.5) Floating – Good quality cement floats in water for some time before sinking. Always make sure to buy the best quality of cement available. Maha Cement, with its attention to detail and world-quality upkeep and process, is known to be the best cement in India.
How do you store cement for a long time?
Storing cement Refrain from storing it in damp, moist environments. Instead, store them in a dry, enclosed area which is protected from rain. Stacking cement bags should be covered with tarpaulin or waterproof sheets.
What does 42.5 mean in cement?
Cement strengths The strength development of a cement is not only defined by the composition but also by the grinding fineness, divided into classes (32.5 – 42.5 – 52.5), This classification takes place based on a pressure test after 28 days. Within each strength class the performances define from an early stage the distinction between the ‘Normal’ (N) and ‘Rapid’ (R) version. The mortar prisms are based on a standard ratio of cement, water and sand. The strength indication for cement has only a limited effect on the strength of concrete or mortars to be achieved. This is because a type of concrete with among others a lower water-cement factor (the ratio of cement as opposed to water) than the type of mortar can be created, which is used for the strength classification of cement. The composition of the aggregate also has an effect on the final strength of concrete. For this reason, the strength class of cement cannot be traced back to a maximum strength class for concrete or mortar. Class 32.5 is indicated for applications where a high initial strength is not required, at average ambient temperatures (10 – 15°C) and with constructions of standard thicknesses (< 50 cm). Cements with strength class 42.5 are mostly used in the event that the required compressive strength of concrete at 28 days must exceed 30 N/mm² (i.e. higher than class C25/30 according to NBN B 15-001). These cements are also suitable for use at lower temperatures. Class 52.5 is used for applications where an even higher initial strength than class 42.5 is required.E.g. for the rapid stripping of prefabricated elements. : Cement strengths
What is cement code?
List of referred Indian Standard Codes for civil engineers
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A large number of Indian Standard (IS) codes are available that are meant for virtually every aspect of civil engineering one can think of. During one’s professional life one normally uses only a handful of them depending on the nature of work they are involved in.
Civil engineers engaged in construction activities of large projects usually have to refer to a good number of IS codes as such projects entail use a variety of construction materials in many varieties of structures such as buildings, roads, steel structures, all sorts of foundations and what not. A list of these codes can come in handy not only for them but also for construction-newbies, students, etc.
The list provided below may not be a comprehensive one, yet it definitely includes some IS codes quite frequently used (while a few of them occasionally) by construction engineers. The description of the codes in the list may not be exactly the same as that written on the covers of the codes.
- IS: 456 – code of practice for plain and reinforced concrete.
- IS: 383 – specifications for fine and coarse aggregate from natural sources for concrete.
- IS: 2386 – methods of tests for aggregate for concrete. (nine parts)
- IS: 2430 – methods of sampling.
- IS: 4082 – specifications for storage of materials.
- IS: 2116 – permissible clay, silt and fine dust contents in sand.
- IS: 2250 – compressive strength test for cement mortar cubes.
- IS: 269-2015 – specifications for 33, 43 and 53 grade OPC.
- IS: 455 – specifications for PSC (Portland slag cement).
- IS: 1489 – specifications for PPC (Portland pozzolana cement).
- IS: 6909 – specifications for SSC (super-sulphated cement).
- IS: 8041 – specifications for RHPC (Rapid Hardening Portland cement)
- IS: 12330 – specifications for SRPC (sulphate resistant portland cement).
- IS: 6452 – specifications for HAC for structural use (high alumina cement).
- S: 3466 – specifications for masonry cement.
- IS: 4031 – chemical analysis and tests on cement.
- IS: 456; 10262; SP 23 – codes for designing concrete mixes.
- IS: 1199 – methods of sampling and analysis of concrete.
- IS: 516BXB JWJJS– methods of test for strength of concrete.
- IS: 13311 – ultrasonic testing of concrete structures.
- IS: 4925 – specifications for concrete batching plant.
- IS: 3025 – tests on water samples
- IS: 4990 – specifications for plywood formwork for concrete.
- IS: 9103 – specifications for concrete admixtures.
- IS: 12200 – specifications for PVC (Polyvinyl Chloride) water bars.
- IS: 1077 – specifications for bricks for masonry work.
- IS: 5454 – methods of sampling of bricks for tests.
- IS: 3495 – methods of testing of bricks.
- IS: 1786 – cold-worked HYSD steel rebars (grades Fe415 and Fe500).
- IS: 432; 226; 2062 – mild steel of grade I.
- IS: 432; 1877 – mild steel of grade II.
- IS: 1566 – specifications for hard drawn steel wire fabric for reinforcing concrete.
- IS: 1785 – specifications for plain hard drawn steel wire fabric for prestressed concrete.
- IS: 2090 – specifications for high tensile strength steel bar for prestressed concrete.
- IS: 2062 – specifications for steel for general purposes.
- IS: 226 – specifications for rolled steel made from structural steel.
- IS: 2074 – specifications for prime coat for structural steel.
- IS: 2932 – specifications for synthetic enamel paint for structural steel.
- IS: 12118 – specifications for Polysulphide sealants
How long does unopened cement last?
Q. Is there a shelf life for portland cement, or will it last indefinitely? A. If kept dry, portland cement will retain its quality indefinitely. However, bagged cement that’s stored for long periods in a dry atmosphere can develop what’s called warehouse pack, a mechanical compaction that makes the cement lumpy.
How long can cement mix be stored?
How long is the shelf-life of concrete mix? – The shelf-life of concrete mix usually varies from a couple of months to several. If it has been stored in an airtight container in an environment where the temperature and humidity have been controlled (which is highly unlikely), it may last up to a year.