This is one of the oldest non-destructive tests and it is still widely used. It was devised in 1948 by Ernst Schmidt, and is therefore known also as Schmidt hammer, or sclerometer, test. The hardness measured by the rebound hammer is quite different from the hardness determined in tests on metals which involve indentation. Rebound … Read more
Solution of the sulfates of various bases including sodium, potassium, magnesium and calcium react with hydrated cement paste forming gypsum or a compound called ettringite (sulphoaluminate) which leads to the expansion and disruption of the concrete and mortar this process is referred as sulphate attack. Sulphate attack is a chemical break down mechanism where suphate … Read more
Quality of concrete depends on many factors among which the most vulnerable and defenseless is workmanship. During pouring the concrete and execution of work cautious supervision is imperative. The supervisor has to look for many things including the finishing of concrete, pouring quantity, at-site testing, unremitting and continual supply of material from the batching plant. … Read more
Materials added to concrete during or before mixing are referred to as admixtures. They are used to improve the performance of concrete in certain situations as well as to lower its cost. There is a rather well-known saying regarding admixtures, to the effect that Different Types of Admixtures “they are to concrete as beauty aids … Read more
Structural lightweight aggregate concrete is an important and versatile material in modern construction. I has many and varied applications: multistory building frames and floors, curtain walls, shell roofs, folded plates, bridges, prestressed or precast elements of all types, and others. In many cases the architectural expression of form combined with functional design can be achieved … Read more