Comparative tests on building stone from college quarries and on concrete building blocks

Abstract

Introduction: To persons located in parts of Kansas where both stone and brick are difficult and expensive to obtain, this set of experiments, carried on at the Kansas State Agricultural College, will be of particular interest. Much has been said for and against concrete as a building material; those who look askance at its claims stating that it is impossible to manufacture a cement which will successfully withstand all the varying conditions, and trials to which any building material will be more or less subjected. They cite as examples the various fires which have occurred over the country and the behavior of buildings constructed from concrete during such fires. The object of investigation which forms the body of this thesis is three-fold. 1. To compare the strengths of the stone and concrete blocks. 2. To determine the comparative effects of fire on both materials when subjected to intense heat as they would be in a building. 3. To compare the strengths of the stone and concrete blocks after they had been subjected to the fire test. The first test was accomplished by treating the blocks and stones as beams supported at the ends and loaded in the middle, the span being 18". The load was applied by means of the 100,000# Riehle Testing Machine in the Mechanical Laboratory. From the breaking load the Modulus of Rupture is easily obtained by means of the formula F = MY/I where F = Modulus of Rupture, M = the bending moment, Y = the distance of the most strained fibre from the neutral axis, and I = the moment of inertia of the section, and this modulus is taken as the basis of comparison between the strengths of the concrete and stone.