3D打印建筑砂浆的工作性和可建造性及其影响因素

Workability and buildability of 3D printing mortar and its influencing factors

研究了聚合物、矿物掺和料、骨料等对3D打印建筑砂浆的可挤出性、出料连续性、堆积性能以及层间衔接性能的影响。结果表明:不掺聚合物或乳胶粉(FX)、塑化剂(KHC)单掺及两者复掺时3D打印建筑砂浆的挤出性较差,掺加保塑剂(HMC)有利于打印砂浆的挤出,HMC与FX复掺可进一步改善打印砂浆的挤出性能。掺加复合矿物掺和料,采用合适的骨料,且HMC、FX和KHC同时掺加时,打印砂浆具有良好的挤出性能、出料连续性、较小的塑性变形,实现了较大的有效堆积高度。采用优化配比打印的建筑构件,层间衔接良好,无宏观缺陷。打印砂浆的工作性、可建造性与其流动度或容重没有必然关系,传统的砂浆流动性无法有效表征3D打印砂浆的工作性。

The effects of polymer,mineral admixture and aggregate on extrudability,discharging continuity,stacking property and interlayer interface of 3D printing mortar are studied.The test results show that the extrusion property of 3D printing mortar is poor when polymer is not added,or FX and KHC are single-doped or doped together.HMC and the mixing of HMC and FX are benefit to the extrudability of printing mortar.When the composite mineral admixture is mixed with suitable aggregate,and HMC,FX and KHC are mixed at the same time,the printing mortar has good extrusion performance,discharge continuity,small plastic deformation,and can achieve a large effective stacking height.Printing the building component by using the optimized proportion,the interface between the layers is good,and there is no macroscopic defect.There is no definite relationship between the workability,buildability and the fluidity or bulk density of the printing mortar.The traditional mortar fluidity cannot effectively characterize the workability of the 3D printing mortar.