硫铝酸盐水泥和膨胀剂对3D打印混凝土性能影响试验研究

Experimental study on influence of sulphoaluminate cement and expansive agent on performance of 3D printing concrete

3D打印技术在建筑领域的快速应用有赖于与打印机相兼容的高性能水泥基材料的制备。收缩开裂及耐久性是决定3D打印混凝土长期使用寿命的关键影响因素。通过掺入硫铝酸盐水泥、高效膨胀剂制备一种低收缩高耐久性3D打印混凝土,测试评估3D打印材料的可打印性、收缩和耐久性。同时采用SEM对该材料的水化产物和微观结构进行分析。结果表明:硫铝酸盐水泥掺量为15%~20%时,材料具有优异的可打印性能,膨胀剂掺量为3.0%时,120 d试件尺寸变化率为0.0528%,收缩率小,抗裂性能好;水化产物结构致密,耐久性好,抗氯离子达到RCM-V等级,120 d碳化满足T-Ⅳ等级,抗硫酸盐符合KS90要求,抗冻融符合F100冻融循环要求。

The rapid application of 3 D printing technology in the field of construction depends on the preparation of highperformance cement-based materials compatible with printers. Shrinkage cracking and durability are key factors that determine the long-term service life of 3 D printing concrete. A low-shrinkage and high-durability 3 D printing concrete was prepared by incorporating sulfoaluminate cement and high-efficiency expansive agent,and the printability,shrinkage and durability of 3 D printing materials were tested and evaluated. At the same time,SEM was used to analyze and study the hydration products and microstructure of the material. The results show that:when the content of sulphoaluminate cement is 15%~20%,the material has excellent printability,when the content of expansive agent is 3.0%,the 120 d dimensional change rate of specimen is 0.0528%,with low shrinkage rate and good crack resistance. The hydration product has a compact structure and good durability,the chloride ion resistance reaches the RCM-V level,the 120 d carbonization meets the T-IV level,the sulfate resistance meets the KS90 requirements,and the freezethaw resistance meets the F100 freeze-thaw cycle requirements.