Aim To determine volume of concrete per bag of cement, where nominal maximum size of aggregate does not exceed 38 mm. Apparatus Balance – Sensitive to 0.01 kg Tamping bar – Length 38 cm, Weight 1.8 kg Cylindrical mould – Dia = 250 mm, Height = 280 mm, Capacity = 0.01m3 Procedure Step-1 (Measuring Volume … Read more
What is Crazing on Concrete Surface? Crazing is the development of fine shallow hair cracks on create surface. Due to crazing the surface appearance of concrete looks not so pleasing. This may appear within few day after curing or sometimes after a longer periods. These cracks do not penetrate deep onto the concrete and do … Read more
What is Slump Loss in Concrete? Slump value is of great importance when concrete is in its fresh state. Slump value represents the workability property of concrete. Due to its importance, the value of slump is generally specified by the designer. And while working on site, the engineer’s responsibility is to make sure that the … Read more
Sulphates present in soil or water can cause serious damages to concrete. The methods given below can be adopted to protect concrete from sulphate attack. Use of Sulphate Resisting Cement The most efficient method of resisting the sulphate attack is to use cement with the low C3A content. It has been found that a C3A … Read more
Factors Affecting Strength Test Results of Concrete Compressive strength is the most important property of concrete. The compressive strength of concrete is determined in the laboratory in controlled conditions. On the basis of this test result we judge the quality of concrete. But sometimes the strength test results vary so widely that it becomes difficult … Read more
Capping of Concrete Cylinders Capping is required to give a smooth surface for applying compressive load to concrete cylinders. Only cylindrical concrete test specimens are capped using appropriate method. When the ends of cylindrical test specimens are not plane within 0.05 mm, it is required to cap those test specimens. The capped surfaces should be … Read more
This simple and quick field test will give you a rough idea of bearing capacity of soil. Procedure Excavate a pit of required depth. (preferably equal to the depth of foundation) Take a solid ball or square cube of known weight and dimension. Drop the ball or square cube several times, from a known height … Read more
Advantages of PPC in Fresh Concrete Portland pozzolana cement (PPC) has following advantages when concrete is in its fresh state. 1. Workability Portland pozzolana cement has spherical cement particles and they have higher fineness value. Due to the spherical shape concrete move more freely and more fineness of particles allows better filling of the pores. … Read more
Aim To determine volume of concrete per batch, where nominal maximum size of aggregate does not exceed 38 mm. Apparatus Balance – Sensitive to 0.01 kg Tamping bar – Length 38 cm, Weight 1.8 kg Cylindrical mould – Dia = 250 mm, Height = 280 mm, Capacity = 0.01m3 Step by Step Procedure to Calculate … Read more
Techniques Used for Improving Bearing Capacity of Soil The following techniques can be used for improving bearing capacity of soil as per the site condition. Increasing depth of foundation Draining the soil Compacting the soil Confining the soil Replacing the poor soil Using grouting material Stabilizing the soil with chemicals 1. Increasing Depth of Foundation … Read more