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what precautions should be taken during the cube test?
aviratdhodare
Precautions for use of concrete compressive testing machine: 1. The operation should be carefully checked and carefully operated according to the steps before starting and operation, and illegal operation is strictly prohibited.2. When operating, it is strictly forbidden to exceed the marking line oRead more
Precautions for use of concrete compressive testing machine:
1. The operation should be carefully checked and carefully operated according to the steps before starting and operation, and illegal operation is strictly prohibited.
See less2. When operating, it is strictly forbidden to exceed the marking line on the vertical column (50mm).
3. It is strictly forbidden to start the motor at high pressure to avoid damaging the electrical appliances.
4. Always check whether the hydraulic oil of the tank is sufficient, and the oil standard shall prevail.
5. Replace the hydraulic oil and clean the tank every half year when using frequently.
The problems faced by a civil engineer during construction?
nikeetasharma
There are many types of problems which are faced by civil engineers during construction, they are:- 1. Environmental problem 2. Climatic condition 3. Geographical topography 4. Health problem 5. Safety problem 6. Manpower problem
There are many types of problems which are faced by civil engineers during construction, they are:-
1. Environmental problem
See less2. Climatic condition
3. Geographical topography
4. Health problem
5. Safety problem
6. Manpower problem
How to adjust mix proportions if we have to work with wet sand?
AdityaBhandakkar
Hi, The maximum amount of water to cement ratio should be determined by the authority having jurisdiction based on the exposure conditions. The targeted water to cement ratio should be selected from the data available on the materials which actually used. but if such data is not available then waterRead more
Hi,
The maximum amount of water to cement ratio should be determined by the authority having jurisdiction based on the exposure conditions. The targeted water to cement ratio should be selected from the data available on the materials which actually used.
but if such data is not available then water to cement the should be selected from IS mix proportion table or ACI Table 6.9.4-a.
See lesswhat is the need to design a mix in concrere
AdityaBhandakkar
Hi, mix producers always work to find the perfect proportions of ingredients to optimize the concrete mixes to give their great concrete strength, durability, enough workability and various desirable properties. It’s very important to optimize the concrete to confirm the lowest expense while maintaiRead more
Hi,
mix producers always work to find the perfect proportions of ingredients to optimize the concrete mixes to give their great concrete strength, durability, enough workability and various desirable properties. It’s very important to optimize the concrete to confirm the lowest expense while maintaining the highest strength of your mix. as every mixing of the concrete mix involves adjustments to the ingredients, making the process very difficult and ineffective.
In this way, mix design is very important to make a project economical, strong and durable.
See lessWhy water is not used to find specific gravity of cement?
nikeetasharma
Specific gravity of any material is defined as the ratio of weight of a volume of a material to the weight of same volume of water at particular temperature. So in this test the quantities are very important. Water is not used in testing of specific gravity of cement because cement reacts with waterRead more
Specific gravity of any material is defined as the ratio of weight of a volume of a material to the weight of same volume of water at particular temperature. So in this test the quantities are very important. Water is not used in testing of specific gravity of cement because cement reacts with water and form compounds. Thus , the quantities measured prior to the commencement of test will not be same after the test. Therefore kerosene which is inert (non-reactive) with cement is used. We should observe here that we calculate the specific gravity of cement with respect to kerosene and convert it with respect to water by using 0.79 (specific gravity of kerosene) in the formula of the same.
See lessWhat is the Mechanism Involved in Resin Transparent Concrete?
Komal Bhandakkar
Mechanism of resin transparent concrete: Construction Materials: PO43.5R OPC (Dalian Xiaoyetian Cement Co., Ltd.) River Sand(Fineness Modulus=2.9) Grade I fly ash Polycarboxylic acid superplasticizer( powder) The light transmission rate of resin transparent concrete is 80% more than transparent concRead more
Mechanism of resin transparent concrete:
Construction Materials:
The light transmission rate of resin transparent concrete is 80% more than transparent concrete using Plastic Optical Fibres.
The number of resins is inserted within the concrete to transmit light from it’s one face to another.
The casting process of resin transparent concrete is the same as that of our conventional concrete but we have to produce a special type of molds that has holes of appropriate spacing.
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How to check the purity of cement?
aviratdhodare
Color test - It sould be uniform light greenish grey. Presence of lumps - There should not be any hard lumps or any other impurities. Adulteration test - Taken pinch of cement in between fingers, it should be smooth, not rough. Temperature test - When inserted hand in cement bag, it should feel coolRead more
- Color test – It sould be uniform light greenish grey.
- Presence of lumps – There should not be any hard lumps or any other impurities.
- Adulteration test – Taken pinch of cement in between fingers, it should be smooth, not rough.
- Temperature test – When inserted hand in cement bag, it should feel cool.
- Float test – Handful of cement if thrown in a bucket full of water, its particles should float on surface for sometime.
- Setting test – Thick paste of cement with water is made on a piece of glass plate and
- Date of packing – Remember the strength of cement reduces with time so it’s important to check the manufacturer time. Cement should be used before 90 days from manufacturing date.
See lessit skipped under water for 24 hours so after 24 hours it will sit and not blend or crack in water.
Sugar is act as an accelerator or retarder in concrete?
aviratdhodare
Introduction : Hydration is the process in which cement mixes with sand, gravel and water to harden and form the mixture we call concrete. Sugar (yes, the white sugar used in households) behaves like a Retarding Admixture and reduces the rate of hydration reaction of cement. Sugar is very effective,Read more
Introduction : Hydration is the process in which cement mixes with sand, gravel and water to harden and form the mixture we call concrete.
Sugar (yes, the white sugar used in households) behaves like a Retarding Admixture and reduces the rate of hydration reaction of cement.
Sugar is very effective, even in minute quantities. To such an extent that, an excess of sugar content in the concrete mix by weight of 0.2% will impede the hydration reaction completely. As a result, the concrete will never set, and collapse immediately once the shuttering is removed. This process is known as Killing of Set.
It is generally done in hot weather conditions to counter the hardening process due to high temp.
Sugar based soln’s are sometimes added to the mix when workers need to keep the mix moist.
The setting time increases with the increase in % of sugar up to 0.06%.
The delay in setting of concrete could be useful in preventing cold joints & in reducing early setting of cement in hot weather concreting.
Sugar when used in right proportions acts as retarder but when it is used in excess, it reverse the property i.e., becomes accelerator.
Sugar above 0.08% by wt of cement accelerated the setting time with nominal gain in initial strength.
So a careful using of sugar can be economical compared to chemical retarder products
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