Compressive Strength Test of Hydraulic Cement Mortar Purpose The following covers only that portion of ASTM Designation: C 109 that is required to determine the compressive strength of 50 mm (2 inches) of Portland cement mortar cubes. Equipment and Materials A 2kg scale accurate to 0.1 gram Six 50 mm (2 inch) cube molds Hard … Read more
Rodded Unit Weight of Coarse Aggregate Purpose Determination of the unit weight of coarse aggregates in a compacted condition. This test method is applicable to aggregates not exceeding 15 cm (6 inches) in nominal size. The unit weight so determined is necessary for the design of a concrete mixture by the absolute value method. Equipment … Read more
Quality Requirement of Fly Ash Bricks 1. 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 uniform in colour The proportion of soil and fly ash shall be as per IS-2117-1991. Fly ash used to manufacture of … Read more
Advantages of Prestressed Concrete Most of the prestressed members are precast and therefore all the advantages or precast concrete hold true for prestressed concrete also. To know the advantages of precast concrete click here. In addition, there are advantages to be gained by prestressing when conditions are favorable to its use. Following additional advantages due … Read more
HOLLOW CONCRETE BLOCK MASONRY Concrete blocks having core void area larger than 25% of the gross area is termed as hollow concrete blocks. These blocks are manufactured in different shapes and sizes as shown in the following figure. Some of the standard sizes of hollow concrete blocks are as follow. Standard size hollow concrete block … Read more
Laboratory Vane Shear Test of Soil Aim To determine shear strength of clay soil using laboratory vane shear apparatus. Theory In soil, shear strength is contributed by the two properties. Cohesion, and Angle of internal friction In pure clays the shear resistance due to internal friction is negligible. Hence, the complete shear strength in clays … Read more
Tests on Aggregate Aggregate plays an important role in pavement construction. Aggregates influence, to a great extent, the load transfer capability of pavements. Hence it is essential that they should be thoroughly tested before using for construction. Not only that aggregates should be strong and durable, they should also possess proper shape and size to … Read more
Lab Tests on Bitumen to Check Quality Various tests are conducted on bitumen to assess its consistency, gradation, viscosity, temperature susceptibility, and safety. There are a number of tests to assess the properties of bituminous materials. The following tests are usually conducted to evaluate different properties of bituminous materials. Penetration test Ductility test Softening point … Read more
Causes of Stone Deterioration The various natural agents such as rain, heat, etc. and chemicals deteriorate the stones with time. 1.Rain Rain water acts both physically and chemically on stones. The physical action is due to the erosive and transportation powers and the latter due to the decomposition, oxidation and hydration of the minerals present … Read more
Defects in Paint Work The defects which are commonly found in paint work are as follow. 1. Blistering Formation of bubbles like shapes on the painted surface is known as blistering. The primary cause of this defect is water vapor. When water vapor trapped under the paint layer, it creates bubbles under the film of … Read more