Plastic shrinkage cracking (as shown below) is caused by rapid drying of the concrete surface. They can occur at any time of the year, from cooler low-humidity weather conditions to, in particular, hot weather conditions involving any one or a combination of high temperature, low humidity and wind. These types of cracks occur while the … Read more
Theory The bond strength is the measure of the effectiveness of the grip between concrete and steel and has no standard quantitative definition. In pull out tests on plain bars, the maximum load generally represents the bond strength that can be developed between concrete and steel. With plain bars the maximum load is not very … Read more
Principle for Supervision of Stone Masonry The following principles should be followed during construction of stone masonry: The stone used in masonry should be durable and strong. All stones should be well watered before laying to avoid absorption of moisture from mortar. All stones should be properly dressed. The stones should be laid on their … Read more
Timber Classification The terms timber and wood are often used synonymously, but they have distinct meanings in the building industry. Wood is the hard, fibrous material that makes up the tree under the bark, whereas timber may be defined as a wood which retains its natural physical structure and chemical composition and is suitable for … Read more
Measurement of Density of Soil in place by Nuclear Density Gauge Purpose This is a quick method of determining the in-situ density of soil which is based on the radiation. Equipment For this test special equipment which measures in place density using gamma radiation is used. Gauge usually contains a small gamma source (about 10 … Read more
Water Content Test of Soil by Alcohol Method Purpose It is a rapid method of determining the moisture content. Though less accurate, it is more suitable as a field test. The method shall not be used if the soil contains a large proportion of clay, gypsum, calcareous matter or organic matter. Apparatus Evaporating Dish– 10 … Read more
Moisture Content Determination Using Rapid Moisture Meter Purpose The purpose of this test is to determine the moisture content of soil quickly, without having to wait for the moisture to evaporate. Soil Specimen This test requires about 6 g of soil sample. Sand requires no special preparation. Coarse powders may be ground and pulverized. Cohesive … Read more
Soil Test to Find Organic Matter Content in Soil Purpose Deleterious contents of soil such as organic matter affect its characteristics and behavior adversely and must therefore be within 2%. Procedure Take an air dried sample of soil and determine its moisture content. Using another sample, produce about 100 g of soil passing the 10 … Read more
Drum Type Concrete Mixer Classification This is also called as free fall mixer or gratify mixer. In this type of mixer, concrete is mixed by lifting the ingredients with the help of fixed blades inside a rotating drum and then dropping the material by overcoming the friction between the mixture and the blades. The drum … Read more
Quality Assurance for Cement Plastering Plastering is a process of applying one or more coats of mortar to a concrete surface, brickwork, stone masonry or lathing. It must be durable such that it resists the penetration of moisture and should be able to weather uniformly. It should also be pleasing in appearance. These properties depend … Read more