烧结保温空心砌块薄灰缝砌体基本力学性能试验研究

Experimental study on basic mechanical properties of fired heat-insulation hollow block thin mortar joint masonry

通过对烧结保温空心砌块薄灰缝砌体受压性能试验和受剪性能试验研究,分析了该类砌体受压、受剪的破坏机理和破坏特征。试验结果表明:只有表面高平整度的砌块才适用于薄灰缝砌体;由于竖缝无砂浆,造成此处应力集中现象明显,受压破坏时沿竖缝形成上下通缝;砌块表面黏结强度不足,需改善生产工艺提高其强度;受剪破坏包括单剪破坏和双剪破坏;通过引入孔洞率影响系数建立了砌体抗压强度计算式,根据抗剪强度试验结果建立了砌体沿通缝截面抗剪强度计算式,计算结果与试验结果吻合较好;根据已有的受压本构模型建立了烧结保温空心砌块砌体受压应力-应变关系和弹性模量计算表达式,与试验结果吻合较好,并建议泊松比的取值为0.3。

Through the experimental study on compressive property and shear strength of fired heat-insulation hollow block thin mortar joint masonry, the damage mechanism and damage characteristics were analyzed. The results show that only the high surface roughness block is suitable for thin mortar joint masonry. The stress concentration phenomenon is obvious due to the vertical seam without mortar, thus the continuous seam is formed along the vertical seam. The surface bonding strength of block is insufficient, so the strength needs to improve by adjusting production technology. The shear failure modes include single shear failure and double shear failure. The calculation formula of the compressive strength was established by introducing hole rate influence coefficient, and the calculation formula of the shear strength was established according to the shear strength test results. The calculation results show good agreement with test results. According to the constitutive model of reference, the calculation formulas of the stress- strain relationship and the elastic modulus are put forward, finally the suggested value for the Poisson＇ s ratio is 0. 3.