TEA-DEC复掺对天然水硬性石灰早期硬化过程的影响

Effect of TEA-DEC compounding on the early hardening process of natural hydraulic lime

天然水硬性石灰(NHL)早期强度低、固化慢的特性影响其在石质文物中的广泛应用,提高NHL早期综合性能是一项具有应用价值的研究。三乙醇胺(TEA)是水泥中常用的早强剂,碳酸二乙酯(DEC)是一种高效稳定的CO_(2)吸收剂,文中将两者复掺改性天然水硬石灰浆体,以提高早期硬化反应效率和力学强度。结果表明,复掺改性使TEA与DEC能够发挥出高效的协同作用,促进水化和碳化反应;降低浆体内部的总孔隙率,促使内部更致密、基体结构更稳定;当TEA-DEC复掺参数质量分数为0.3%、0.5%时,综合改性效果最佳,初凝和终凝时间分别缩短了18%和45.5%,力学性能得到明显改善,养护28 d时抗压强度可提高27.3%,相当于欧洲标准中NHL5的强度水平。

The low early strength and slow curing characteristics of natural hydraulic lime(NHL)limit its wide application in stone cultural relics.Improving its early comprehensive performance is a study with significant practical value.Triethanolamine(TEA)is a commonly used early-strengthening agent in cement,while diethyl carbonate(DEC)is a highly efficient and stable CO_(2)absorber.In this paper,we combine the advantages of these two materials to compound-modify natural hydraulic lime slurry(NHL)to improve the efficiency of early hardening reactions and mechanical strength.The results show that the compounding modification of TEA and DEC exhibites an efficient synergistic effect,significantly promoting hydration and carbonation reactions.The total porosity within the slurry is reduced,contributing to a denser and more stable matrix structure.The optimal modification effect is achieved with TEA-DEC mass fraction of 0.3%and 0.5%..The initial and final setting times are shortened by 18%and 45.5%,respectively.The mechanical properties are obviously improved,with compressive strength increased by 27.3%after 28 days of maintenance,reaching the strength level of NHL5 in the European standard.