水泥路面板芯样的压缩试验及流变特性

Compression Test and Rheological Analysis of Concrete Cored in Cement Pavement

为了研究水泥路面在服役若干年后混凝土面板力学行为和技术性能的变化,并为水泥路面的结构设计、性能评价和养护维修等提供理论参考,在通车已达16年的水泥路面中钻芯取样,并在实验室制作了同标号水泥混凝土试件用以对比分析;将这2种新、旧混凝土圆柱体试件在3个加载速率下按照"简单加载至破坏"和"循环加载后至破坏"2种加载方式进行压缩试验。试验结果表明:新混凝土具有1个屈服应力,而旧混凝土则有2个屈服应力;在第一屈服应力的80%范围内和较高加载速率下,混凝土主要表现为线弹性,较低加载速率时才会表现出微量粘性;弹性模量的取值可采用"80%度量法"的割线模量;水泥路面板服役16年后,其抗压弹性模量和抗压极限应力分别衰减了约29%和56%。

To study the mechanical behavior and the technical properties of cement pavement slabs after several years＇ service and provide theoretical reference for the structure design, performance evaluation and maintenance of cement pavement, old concrete samples were obtained by coring cement pavement which had been in service for 16 years, and new concrete samples with the same strength grade were made in laboratory for comparative analysis. Then with two types of loadings, ＂simple loading to failure＂ and ＂cyclic loading to failure＂, compression tests were conducted on these two kinds of new and old concrete cylindrical samples under 3 loading rates. The results show that the new concrete possesses one yield of stress and the old concrete has two yields; the concrete is a linear elastic body in the range of 80% of first yield stress and under higher loading rate, but presents minor viscosity under lower rate; the modulus of elasticity may be approximately obtained by the secant modulus, named as ＂method of 80%＂; the compressive modulus of elasticity and compressive ultimate stress of the old concrete after 16 years＇ service have decreased about 29% and 56% respectively.