次轻页岩集料混凝土抗折与抗压强度换算关系研究

Study on the Conversion Relationship Between the Flexural Strength and Compressive Strength of Specified Density Shale Aggregate Concrete

为了研究次轻页岩集料混凝土的立方体抗压强度和抗折强度,以及两者之间的换算关系,以取代率为变化参数,开展了次轻页岩集料混凝土的立方体抗压强度和抗折强度试验。获取了次轻页岩集料混凝土的受力破坏形态,探讨了取代率对次轻页岩集料混凝土抗折强度与立方体抗压强度开根号的比值(类折压比)的影响规律,并建立了次轻页岩集料混凝土的类折压比与取代率之间的换算关系。研究结果表明:次轻混凝土的立方体试块受压破坏时呈倒三角形破坏形式,棱柱体试块抗折破坏时表现为脆性破坏;随着碎石、河砂取代率的增加,次轻页岩集料混凝土的类折压比逐渐增加;通过引入取代率影响参数,分别建立了石轻混凝土、砂轻混凝土类折压比与取代率之间的换算关系式,该关系式简单实用、计算精度较高。

To study the cube compressive strength and flexural strength as well as conversion relationship between the two for specified density shale aggregate concrete,with the replacement rate of lightweight aggregate as change parameter,experiments on the cube compressive strength and flexural strength were carried out on the specified density shale aggregate concrete. The failure modes of specified density shale aggregate concrete were obtained,the influence the replacement rate made on the ratio of flexural strength to the square root of compressive strength（ defined as Similar Flexural-Compressive Ratio（ SFCR）） for specified density shale aggregate concrete were discussed,the conversion relationship between SFCR and replacement rate was established. The results show that the cube specimens of specified density shale aggregate concrete show the inverted triangle-shaped failure form based on the experiment of cube compressive strength,and the prism specimens is characterized by brittle failure under the flexural experiment. With the increase of gravel or river sand replacement rate,the SFCR of specified density shale aggregate concrete increases gradually. By the introduced parameter in association with the replacement rate,the conversion relationship between SFCR and the replacement rate of stone-lightweight aggregate concrete and sand-lightweight aggregate concrete is established respectively,which is simple,practical and the calculation accuracy is relatively high.