Welcome to AffordableConcreteCutting.Net

“We Specialize in Cutting Doorways and Windows in Concrete Foundations”

Are You in Mont Vernon New Hampshire? Do You Need Concrete Cutting?

We Are Your Local Concrete Cutter

Call 603-622-4441

We Service Mont Vernon NH and all surrounding Cities & Towns

“No Travel Charges – Ever! Guaranteed!”

Concrete Cutting Mont Vernon NH         

Concrete Cutter Mont Vernon NH           

Concrete Coring Mont Vernon NH          

Core Drilling Mont Vernon NH                 

Concrete Sawing Mont Vernon NH

Concrete Sawing Mont Vernon New Hampshire

Concrete Cutting Mont Vernon New Hampshire          

Concrete Cutter Mont Vernon New Hampshire

Concrete Coring New Hampshire           

Core Driller Mont Vernon NH                   

Core Drilling Mont Vernon New Hampshire                  

Although such concrete is theoretically subject to tension, and does actually contribute its share of the tension when the stresses in the concrete beam are small, the proportion of the necessary tension which the concrete can furnish when the concrete beam is heavily loaded, is so very small that it is usually ignored, especially since such a policy is on the side of safety, and also since it greatly simplifies the theoretical calculations and yet makes very little difference in the final result. We may therefore consider that in a unit-section of the concrete beam, as in Fig. 92, the concrete above the neutral axis is subject to compression, and that the tension is furnished entirely by the steel. In computing the transverse stresses in a wooden concrete beam or steel I-concrete beam, it is assumed that the modulus of elasticity is uniform for all stresses within the elastic limit. Experimental tests have shown this to be so nearly true that it is accepted as a mechanical law. This means that if a force of 1,000 pounds is required to stretch a bar .001 of an inch, it will require 2,000 pounds to stretch it .002 of an inch. Similar tests have been made with concrete, to determine the law of its elasticity. Unfortunately, concrete is not as uniform in its behavior as steel. The results of tests are somewhat contradictory. Many concrete construction engineers have argued that the elasticity is so nearly uniform that it may be considered to be such within the limits of practical use. But all experimenters who have tested concrete by measuring the proportional compression produced by various pressures agree that the additional shortening produced by an additional pressure, say of 100 pounds per square inch, is greater at higher pressures than at low pressures. A test of this sort may be made substantially as follows: A square or circular column of concrete at least one foot long is placed in a testing machine. A very delicate micrometer mechanism is fastened to the concrete by pointed screws of hardened steel. These points are originally at a known distance apart—say 8 inches. When the concrete is compressed, the distance between these points will be slightly less. A very delicate mechanism will permit this distance to be measured as closely as the ten-thousandth part of an inch, or to about      of the length. Suppose that the various pressures per square inch, and the proportionate compressions, are as given in the following tabular form: We may plot these pressures and compressions as in Fig. 93, using any convenient scale for each. For example, for a pressure of 800 pounds per square inch, we select the vertical line which is at the horizontal distance from the origin according to the scale adopted. Scaling off on this vertical line the ordinate .00045, according to the scale adopted for compressions, we have the position of one point of the curve. The other points are obtained similarly. Although the points thus obtained from the testing of a single concrete blocks of concrete would not he considered sufficient to establish the law of the elasticity of concrete in compression, a study of the curves which may be drawn through the series of points obtained for each of a large number of concrete blocks, shows that these curves will average very closely to parabolas that are tangent to the initial modulus of elasticity, which is here represented in the diagram by a straight line running diagonally across the figure. It is generally considered that the axis of the parabola will be a horizontal line when the curve is plotted according to this method. The position of the vertex of the parabola cannot be considered as definitely settled. Professor Talbot has computed the curve as if the vertex were at the point of the ultimate compression of the concrete, although he conceded that the vertex might be in an imaginary position corresponding to a compression in the concrete higher than that which the concrete could really endure.

Are You in Mont Vernon New Hampshire? Do You Need Concrete Cutting?

We Are Your Local Concrete Cutter

Call 603-622-4441

We Service Mont Vernon NH and all surrounding Cities & Towns