碱激发矿渣陶砂砂浆砌筑的砌体弯曲受拉性能试验

Experimental study on bending tensile strength of masonry with alkali-activated slag mortar with pottery sand

摘要:

为研究碱激发矿渣陶粒混凝土空心砌块（alkali-activated slag ceramsite concrete hollow block,简称AASCHB）砌体的弯曲受拉性能,完成了108个用Mb25~Mb90碱激发矿渣陶砂砂浆（alkali-activated slag mortar with pottery sand,简称AASM）砌筑的AASCHB砌体的弯曲受拉性能试验.试验结果表明:GB 50003—2011表B.0.1-2中所给公式不能准确预估AASM砌筑的AASCHB砌体的弯曲抗拉强度,砂浆强度低于70.3 MPa时,沿通缝截面弯曲抗拉强度预估值偏高,砂浆强度介于70.3~91.9 MPa时,沿通缝截面弯曲抗拉强度预估值偏低；当砂浆强度低于46.2 MPa时,沿齿缝截面弯曲抗拉强度预估值偏高,砂浆强度介于46.2~91.9 MPa时,沿齿缝截面弯曲抗拉强度预估值偏低.同时发现AASCHB砌体弯曲抗拉强度不但与AASM的抗压强度有关,而且受水灰比、砂灰比、Na₂O含量和水玻璃模数的影响.基于试验结果,分别建立了AASCHB砌体沿通缝截面和沿齿缝截面弯曲抗拉强度的计算公式.

Abstract:

To study the bending tensile performance of alkali-activated slag ceramsite concrete hollow block (AASCHB) masonry, tests on 108 masonry specimens with Mb25~Mb90 of alkali-activated slag mortar with pottery sand (AASM) were carried out. The experimental results show that the formula calculation based on Table B.0.1-2 of GB 50003—2011 cannot exactly estimate the bending tensile strength of AASCHB masonry with AASM. When the compressive strength of mortar was lower than 70.3 MPa, the formula calculation of the bending tensile strength along straight joint was higher than the test result.When the compressive strength of mortar was between 70.3 MPa and 91.9 MPa, the formula calculation of the bending tensile strength along straight joint was lower than the test result. The formula calculation of the bending tensile strength along slot joint was higher than the test result as the compressive strength of mortar was lower than 46.2 MPa.When the compressive strength was in the range of 46.2 MPa to 91.9 MPa, the formula calculation of the bending tensile strength along slot joint was lower than the test result. It was found that the bending tensile strength of AASCHB masonry was not only related to the compressive strength of AASM, but also affected by the factors of water to cementitious material ratio, sand to cementitious material ratio, Na₂O content, and silicate modulus.Based on the experimental results, the formulae for the bending tensile strengths of AASCHB masonry along straight joint and slot joint were developed, respectively.