3D打印混凝土打印性能评价参数的提出及试验验证

Proposal and test verification of 3D printing concrete printing performance evaluation parameters

3D打印混凝土需要同时满足泵送性、挤出性和建造性的要求,其中,对混凝土拌合物的泵送性和建造性的综合评价尤为重要。提出了以流比和稠比表征的材料触变参数,并以3种外加剂(羟丙基甲基纤维素醚(HPMC-6)可再分散乳胶粉(RLP)硅酸镁铝(TL))为研究对象,基于正交试验研究了3种外加剂对3D打印混凝土触变参数的影响规律。研究表明:可以采用提出的触变参数定量地对3D打印混凝土泵送性和建造性进行综合评价,3种外加剂对触变参数的影响程度为HPMC-6>RLP/TL,3种外加剂的掺入都会使材料触变参数的下降。

3D printing concrete needs to meet the requirements of pumpability,extrudability and constructability at the same time,among which the comprehensive evaluation of the pumpability and constructability of concrete mixture is particularly important.It is important to evaluate the printing performance of materials by coupling them.Thixotropic parameters characterized by flow slump ratio and consistency slump ratio are proposed to evaluate the printing performance of materials under the coupling of pumping and construction.Taking hydroxypropyl methyl cellulose ether(HPMC-6),redispersible latex powder(RLP)and magnesium aluminum silicate(TL)as the research objects,based on the orthogonal test,the influence of the three additives on the thixotropic parameters of 3D printing concrete was studied.The research shows that the thixotropy parameters proposed can be used to quantitatively evaluate the pumping ability and constructability of 3D printing concrete.The influence of three additives on thixotropy parameters is HPMC-6>RLP/TL,and the addition of three additives will lead to the decrease of thixotropy parameters of materials.