聚乙烯纤维增强高延性碱矿渣复合材料的拉压性能及裂缝分布

在碱激发作用下，以矿粉为主要原材料，粉煤灰为辅助材料，共同制备聚乙烯(PE)纤维增强高延性碱矿渣复合材料。通过轴向拉、压实验，研究不同养护龄期(1天、3天、7天、28天、56天、120天)下材料的拉压性能，并借助数字图像技术(DIC)对裂缝进行了表征。结果表明:高延性碱矿渣表现出较好的延性，具有早强特征。7天强度值可达极限强度的84%以上(极限拉压强度分别为5.05 MPa、91.24 MPa)，拉伸应变可达5.74%，多缝开裂基本饱和；28天后拉压性能趋于稳定(拉压强度、拉伸应变分别保持在6 MPa、100 MPa、6%)；DIC数字分析云图直观地描述了裂缝的形成及发展过程，可从一定程度上对开裂破坏方向及位置进行可靠预判。 

Tensile and compressive properties and crack distribution of polyethylene fiber reinforced high ductile alkali-activated slag composites

Activated by alkaline activator, polyethylene (PE) fiber reinforced high ductile alkali-activated slag composites were prepared using slag as the main raw material and fly ash as auxiliary material. The tensile and compressive properties of the composites under different curing ages (1 day, 3 days, 7 days, 28 days, 56 days and 120 days) were studied through uniaxial tensile and compressive tests, and the cracks were characterized by a digital image correlation technology (DIC). The results show that the alkali-activated slag owns a good high ductility and early strength. The strength value at 7 days can reach more than 84% of the ultimate strengths (the ultimate tensile and compressive strengths are 5.05 MPa and 91.24 MPa, respectively), 5.74% for the tensile strain, and the multi-cracking is basically saturated. After 28 days, the tensile and compressive properties become stable (tensile and compressive strengths and tensile strain keep around 6 MPa, 100 MPa and 6%, respectively). DIC analysis cloud maps visually describe the formation and propagation of cracks, which can be applied to predict reliably the direction and location of cracks to a certain extent.