机制生土砖砌筑砂浆配方及粘结性能试验研究

Experimental study on formula and bond behavior of mortar which is suitable for the mechanical pressing raw-soil brick

为解决新型绿色建材-机制生土砖的粘结问题,研究专用砂浆配方,分析砂浆掺料性能和掺量比例,提出测试砂浆与生土砖粘结性能的试验方法.配制了4种砂浆,对其7 d、14 d和28 d龄期共72个试件进行拉伸粘结试验,研究砂浆对生土砖粘结的有效性和不同配方砂浆对试件破坏形态、粘结性能的影响,对比不同龄期拉伸粘结强度平均值的变化规律.试验结果表明:复掺0.16%纤维素醚和1.6%胶粉的砂浆28 d拉伸粘结强度平均值最高,可达到0.77 MPa,破坏在生土砖内靠近粘结面约3~5 mm,满足机制生土砖的粘结要求,可作为机制生土砖砌筑砂浆.

In order to solve the problems of bond behavior in the new green building material, i. e. mechanical pressing raw-soil brick, the formula of special mortar was studied, the performance and ratio of admixture were analyzed. The experimental testing method of bond behavior between mortar and mechanical pressing raw-soil brick were presented. Four different mortar were prepared, the tensile bond test of 72 specimens under 7 d, 14 d and 28 d were carried out. Effectiveness of mortar was studied, influence on failure mode and bond behavior of mortar kinds were researched, and meanwhile, the variation of bond strength in different ages were compared. The results show that the highest average bond strength was obtained when mixing 0. 16% cellulose ether and 1. 6% emulsion powder. The average value of 28 days is 0. 77 MPa, the failure surface is in the mechanical pressing raw-soil brick, and the thickness of soil stuck on bond block is 3？5 mm. The bond requirement was satisfied and the mortar can be used as masonry mortar of mechanical pressing raw-soil brick.