Suryakanta What is Admixture? It is an optional ingredient of concrete which is added to modify the properties of fresh and hard concrete and grout materials as per some specific requirements. Addition of admixture may alter workability, pumping qualities, strength development, appearance etc in fresh concrete and permeability, strength, durability etc in hardened concrete. But use … Read more
The followings are general recommendations or considerations for hot weather concreting. Guidelines to Follow 1. Do not exceed the maximum allowable water-cementious materials ratio or the manufacturer’s maximum recommended dosage of any admixture. 2. Consider retarding admixtures if their performance has been verified during trial batches. 3. Substitute ground, granulated blast furnace slag for part … Read more
During hot weather, problems that may occur in concrete include the following. Rapid slump loss Reduced air content Premature stiffening Plastic shrinkage cracks Thermal cracking Therefore it is necessary to keep concrete temperature down. The most effective way to keep concrete temperature down is by controlling the temperature of its ingredients. Among all ingredients of … Read more
Effects of hot weather on concrete, in the absence of special precautions can be as follows. Accelerated setting of concrete Reduction in strength of concrete Increased tendency to crack Rapid evaporation of water during curing period Difficulty in control of air in air-entrained concrete Accelerated Setting The rate of setting time of the concrete increases … Read more
Aim To determine point load strength index of rock as per IS-8764 Equipments Point load strength test machine A 100 mm scale attached with the loading frame Pressure gauge (Capacity 25 kN or 50 kN) Depending upon the size and shape of test specimen, the point load strength index can be conducted by four different … Read more
Hand mixing is adopted for small works and where the quantity of concrete used is small. The following procedure is followed to mix concrete by hand. Procedure Construct a platform of bricks, lean concrete or iron sheets of a size as per requirement of the volume of concrete to be mixed. Spread out the measured … Read more
Why additives used? Additives are used to improve some properties of clay mass, such as Shaping characteristics Drying behavior Firing behavior More than that, some of the additives help in conservation of agricultural land and utilization of waste materials. And remember, additives must contain certain physical and chemical characteristics so that it does not adversely … Read more
Civil engineering structures are of many types, such as road, buildings, bridge etc. The type of building material to use in a civil engineering structure is dependent upon many factors, such as it life time, purpose, loads it must carry, environmental condition it is exposed to etc. Therefore different types of brick are manufactured in … Read more
Bricks are extensively used as building material in most of the construction work. The quality of a structure or building is therefore dependent upon the quality of bricks used there in. We cannot test each and every brick to inspect its quality as it is impractical. That is why a sampling method or procedure must … Read more
General Quality Bricks shall be free from cracks and flaws and nodules of free lime. Bricks shall have smooth rectangular faces with sharp corners Bricks shall be of uniform in colour and texture. Bricks shall be manufactured either by extrusion or by pressing. Two bricks when struck together shall emit a clear metallic ring sound. … Read more