热活化油页岩半焦对混凝土力学性能的影响研究

Effect of thermal activated oil shale semi-coke on the mechanical properties of concrete

为研究热活化油页岩半焦对混凝土力学性能的影响,选取300、400、500和600℃高温煅烧后的油页岩半焦,以5%~25%的掺量替代水泥制备半焦混凝土,测试油页岩半焦混凝土的抗压、抗折强度;借助核磁共振技术分析半焦混凝土内部孔隙信息,剖析半焦混凝土的强度和孔隙率的关系。结果表明:随着油页岩半焦煅烧温度的升高,半焦混凝土的抗压、抗折强度先升后降,500℃时力学性能最好;随着油页岩半焦掺量的增加,半焦混凝土的抗压、抗折强度先升后降,掺量为15%时混凝土力学性能最好;半焦混凝土内部以小孔隙居多,其孔隙率随油页岩半焦掺量的增加先减后增,掺量为15%时混凝土孔隙率最小。

In order to investigate the effect of thermally activated oil shale semi-coke on the mechanical properties of concrete,oil shale semi-coke after high temperature calcination at 300 ℃,400 ℃,500 ℃ and 600 ℃ was selected.Semi-coke concrete was prepared by replacing cement with 5%-25% of the oil shale semi-coke.The compressive and flexural strengths of the semi-coke concrete were tested.The internal pore information of the semi-coke concrete was analyzed by nuclear magnetic resonance,while the relationship between the strength and porosity of the semi-coke concrete was studied.The results showed that with the increase of the calcination temperature for the oil shale semicoke,the compressive and flexural strengths of the semi-coke concrete first increased and then decreased,with the optimal mechanical properties at 500 ℃.With the increase of the oil shale semi-coke content,the compressive and flexural strengths of the semi-coke concrete first increased and then decreased,where the optimal mechanical properties were achieved at a semi-coke content of 15%.The internal structure of the semi-coke concrete had many small pores.The porosity of the semi-coke concrete first decreased and then increased with the increase of the oil shale semi-coke content,where the minimum porosity was obtained at a semi-coke content of 15%.