Cement base pipe mechanical property testing method

Abstract

The invention discloses a cement base pipe mechanical property testing method, and belongs to the field of cement base pipe mechanical property test. A radical compression load is applied on a cement base pipe until the cement base pipe is broken. The elastic modulus and bending strength of the cement base pipe are calculated by a formula (1) and a formula (2) represented in the description respectively. In the formulas (1) and (2), R represents the external radius, r represents the internal radius, b represents the width, [delta]P represents load increment in a linear elasticity range, [delta][delta] represents a compression deformation amount; E represents an elastic modulus, Pmax represents the critical load when the cement base pipe sample is cracked; and [sigma] represents bending strength. The rapid, efficient, and simple measurement of the elastic modulus and bending strength of a cement base pipe is realized, and a large amount of test time ant test cost is saved.

Description

technical field [0001] The invention relates to the field of testing the mechanical properties of cement-based materials, in particular to a method for testing the mechanical properties of cement-based pipes. Background technique [0002] Cement-based materials have been widely used in various fields such as water supply and drainage pipes, underground cable protection pipes, underground optical cable protection pipes, well pipes for farmland machinery, chimney pipes, etc., and are inseparable from human production and life. The safe service of various cement-based pipes It is the premise to ensure people's normal life and social development. The mechanical properties of cement-based pipes are crucial to ensuring their safe service. The elastic modulus is very important for the analysis of the internal force of cement-based pipes, the calculation of component deformation and crack resistance, and flexible modification; the bending strength can determine its withstand The ma...

AI Technical Summary

Problems solved by technology

The above detection method is only applicable to solid prism specimens, and cannot be used to directly measure the bending strength of tubular specimens

[0004] Chinese patent CN102095637A discloses a method for measuring the elastic modulus and bending strength of ring or tubular brittle materials, using the notched ring method to calculate the elastic modulus and bending strength, but this method is only applicable to r / R>9 / 11≈ 0.82 (r—the inner radius of the ring; R—the outer radius of the ring) thin-walled ring samples, and commonly used cement pipes include both thin-walled pipes and thick-walled pipes, such as GB / T 11836-2009 "concrete The specifications of concrete pipes given in "Reinforced Concrete Drainage Pipes" are r / R=0.72~0.83, and the specifications of reinforced concrete pipes are r / R=0.77~0.86, and usually in order to meet the impermeability requirements of cement pipes, it is also required increase its wall thickness

However, the gap ring method needs to prepare a notch on the tubular sample, which will affect the original residual internal stress distribution of the sample, so that the measurement results cannot represent the real mechanical properties of the component.

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