高流动性3D打印水泥基材料制备及性能研究

为了制备性能良好的3D打印胶凝材料,用碱激发剂对粉煤灰/矿渣胶凝材料进行激发得到了满足可打印性和力学性能的基础材料,并分析了影响胶凝材料性能的最主要因素,基于微观试验结果分析了粉煤灰和碱激发剂对胶凝材料性能的影响机理。结果表明:基础材料的合适掺量和组成为:粉煤灰30%、碱胶比0.56%、碱含量5%、激发剂模数1.0;宜选用CaO含量适中的矿渣,激发剂静置时间应为48 h;影响胶凝材料流动性和力学性能的最主要因素为碱含量;相比于纯矿渣胶凝材料,粉煤灰的掺入使材料表面出现微裂缝,使其强度降低,而碱激发剂的掺入,增强了胶凝材料的密实性,提高了强度。

Study on Preparation and Properties of High Fluidity 3D Printed Cement-based Materials

In order to prepare 3D printed cementitious materials with good properties,fly ash/slag cementitious materials were excited by alkali activator,the composition of basic materials satisfying the printability and mechanical properties was obtained,and the main factors affecting the properties of cementitious materials were analyzed.The influence mechanism of fly ash and alkali activator on the properties of cementitious materials was analyzed by microcosmic experiment.The results show that the proper content and composition of the basic materials are as follows:fly ash 30%,ratio of alkali activator soultion to cementitious material 0.56%,alkali content 5%,activator modulus 1.0.The slag with moderate CaO content should be selected and the static time of the activator should be 48 h.The alkali content is the most important factor that affects the fluidity and mechanical properties of cementitious materials.Compared with the pure slag cementitious material,the addition of fly ash causes the micro-cracks on the surface of the material and reduces its strength,while the addition of alkali activator enhances the compactness and strength of the cementitious material.