3D打印矿渣-粉煤灰基地质聚合物混凝土减水剂适用性研究

Applicable water reducing agent for 3D printing slag and fly ash based geopolymer concrete

为了获得适用于3D打印矿渣-粉煤灰基地质聚合物混凝土的减水剂,通过对比试验探究了聚羧酸系高性能减水剂、萘系减水剂、脂肪族高效减水剂和三聚氰胺型减水剂的减水效果,结果表明:萘系减水剂对地质聚合物混凝土的减水效果最好。通过平行试验探究不同萘系减水剂掺量对地质聚合物混凝土凝结时间及力学性能的影响,结果表明:萘系减水剂可以延长材料的凝结时间,且随掺量增加,凝结时间呈指数型增长趋势;当掺量过高时不利于地质聚合物混凝土强度发展;萘系减水剂最佳掺量不应大于矿渣与粉煤灰总质量的1.5%,建议掺量为矿渣与粉煤灰总质量的1%。

To find suitable water reducing agent for 3D printing slag and fly ash based geopolymer concrete,contrast tests were carried out to evaluate the water reducing effects of the polycarboxylic acid series high performance water reducing agent,naphthalene series water reducing agent,aliphatic high efficiency water reducing agent and melamine type water reducing agent.The test results show that the naphthalene series water reducing agent has the best water reducing effect for geopolymer concrete.In addition,parallel experiments were conducted to clarify the effects of different naphthalene water reducing agent contents on the setting time and mechanical properties of geopolymer concrete.The results show that the naphthalene water reducing agent prolongs the setting time of the materials,and the setting time increased exponentially with the increase of the content.Too high content of water reducing agent is not conducive to the strength development of geoppolymer concrete.The optimal content of naphthalene water reducing agent should not be greater than 1.5%of the total mass of mineral powder and fly ash,and the recommended content is 1%of the total mass of mineral powder and fly ash.