ECC型自保温干混砂浆的制备与性能表征1

在普通干混砂浆中掺加木质素纤维,且用膨胀珍珠岩颗粒等量代替普通细集料砂,获得自保温干混砂浆样品,研究其物理力学性能、热学性能及收缩性能等。结果表明：加入占胶凝材料质量0.3%的木质素纤维,能显著改善自保温砂浆硬化后的力学性能,尤其是抗折强度;用膨胀珍珠岩替代砂,膨胀珍珠岩的体积分数小于15%时,能提高含纤维硬化样品的28 d抗压强度,大于15%时,样品的28 d抗压强度会降低,为15%时,砂浆试样硬化后的28 d抗压强度为38 MPa,抗折强度为6.1 MPa;另外,当样品中膨胀珍珠岩体积分数为20%,含胶凝材料质量0.3%的木质素纤维,其硬化后的导热系数仅为基准砂浆样品的1/3。

Preparation and Characterization of ECC-type Dry Mixed Mortar with Heat Insulation

The high-performance dry mixed mortar（DMM） specimens of heat-insulation were obtained after mixing the lignin fibers（LF） and expanded perlite（EP） particles into ordinary DMM. The properties of the dry mixed mortar were characterized systematically, including the physical and mechanical properties, thermal properties and shrinkage properties. It is found that the mechanical properties of the hardened heat-insulation DMM specimens are significantly improved by adding LF at the amount of 0.3% of the mass of their cementitious material, especially the improvement of their flexural properties. When the volume fraction of EP is less than 15%, the 28 d compressive strength is improved with the increase of EP amount for the resulting hardened DMM specimens with LF. When the volume fraction of EP is more than 15%, the 28 d compressive strength is decreased with the increase of EP amount for the resulting hardened DMM specimens with LF. When the volume fraction of EP is 15%, the 28 d compressive strength is 38 MPa for the resulting hardened DMM specimen with LF, and its 28 d flexural strength is 6.1 MPa. In addition, when the volume replacement of the EP to the sands is 20% and the addition of LF is 0.3% of the mass of cementitious material, the resulting hardened DMM specimen has the thermal conductivity only by time of 1/3 of the referencing mortar specimens without EP and LF.