AN EXPERIMENTAL STUDY ON NONDESTRUCTIVE TESTS AND STRESS STRAIN CURVES OF M20 GRADE CONCRETE WITH NANO-SILICA USING M-SAND

Concrete is the world's most widely used construction material because of its versatility, durability, sustainability, and economy. The term concrete refers to a mixture of aggregates, usually sand, and either gravel or crushed stone, held together by a binder of cementitious paste. In India, the conventional concrete is mostly produced by using natural sand obtained from the riverbeds as fine aggregate. One of the important ingredients of conventional concrete is natural sand or river sand. However, due to the increased use of concrete in almost all types of construction works, the demand of natural or river sand has been increased. Thus in order to meet these increased demands of construction industry, excessive quarrying of sand from river beds is taking place which results in the shortage of natural sand. This scarcity of natural sand has forced engineers to find a suitable substitute. One of the best ways of getting substitute for natural sand is by crushing natural stone to get artificial sand of desired size and grade .The use of artificial sand will conserve the natural resources for sustainable development of the concrete in construction industry. Hence the practice of replacing river sand with M-Sand is taking a tremendous growth. In the present study the ordinary portland cement is partially replaced with nanosilica by 2% and natural sand is replaced with manufactured sand in different proportions of 0%,25%,50%,75%,100%.The non destructive tests were performed such as rebound hammer test and ultrasonic pulse velocity method.Here stress strain curves were also plotted along with the calculation of Youngs Modulus.