The process of selecting concrete mixture proportions is a process of optimization of several desirable characteristics based on the project requirements. The characteristics to be optimized are economy, strength, durability, and placeability. 1. Economy. The primary reason for systematically determining mixture proportions is economy. The maximum economy can be achieved by minimizing the amount of … Read more
Rebound Hammer Test The Schmidt rebound hammer is principally a surface hardness tester with little apparent theoretical relationship between the strength of concrete and the rebound number of the hammer. However, within limits, empirical correlations have been established between strength properties and the rebound number. Further, scientist has attempted to establish a correlation between the … Read more
CEMENT AND CONCRETE – ARE THEY THE SAME? Many people think that cement and concrete are the same product – they are not. Cement is a dry powdered chemical that, when mixed with water, slowly reacts to form a new hard, solid compound. On the other hand, concrete is a mixture of cement blended with … Read more
Errors in Chain Surveying Every measurement made with a mechanical device is subject to any error that could possibly be caused by the condition of the device or by the procedure used in taking the measurement. Some of the more common sources of errors are the standards to which the chain was manufactured, any damage … Read more
QUALITY CONTROL OF READY MIX CONCRETE Quality control of ready-mixed concrete may be divided into three components, 1. Forward control, 2. Immediate control and 3. Retrospective control. FORWARD CONTROL: Forward control and consequent corrective action are essential aspects of quality control. Forward control includes the following. • Control of purchased material Quality • Control of … Read more
TIPS ON INCREASING REPETITION VALUE TO PLYWOOD There are many reasons to use plywood as a concrete shuttering materials. Out of those reasons one reason is it’s reuse value. But if proper care has not been taken during handling of plywood then it will not give a higher repetition value. So in this video I … Read more
What Is The Effect of Tree Roots on Building? Fast growing trees close to buildings can cause unequal settlement when active tree roots dry out the soil causing differential soil shrinkage. Shrinking clays affect the bearing capacity and lead to movement in the building, especially in shallow foundations. Tree roots can extend over a considerable … Read more
WEATHERING OF ROCK MASS ‘Weathering is the process of alteration and breakdown of rock and soil materials at and near the Earth’s surface by chemical decomposition and physical disintegration’ (Geological Society Engineering Group Working Party Report, 1995). Of particular note in this definition is that weathering is described as a process. It is not a … Read more
WEIGHT VOLUME RELATIONSHIP OF SOIL The physical properties of a soil give insight as to the identification of the soil and the determination of its characteristics and load response. These properties can be determined by performing a laboratory analysis on undisturbed soil samples obtained during the test boring process. The laboratory analysis should be performed … Read more
PROPERTIES OF HARDENED CONCRETE The following are the properties of concrete in its hardened state, used by the designer during design process of reinforced concrete structure. 1. Compressive Strength The characteristics strength is defined as the strength of concrete below which not more than 5% of the test results are expected to fall. As per … Read more