改性水硬性石灰基材料的制备与性能研究

Study on preparation and properties of modified hydraulic lime-based material

水硬性石灰作为一种传统的硅酸盐建筑材料,广泛应用于历史建筑文物的修复中。研究了矿粉及其它外加剂改性的水硬性石灰的配合比优化设计方法、物理力学性能、水化硬化机理。研究表明:掺加4种外加剂(黏性助剂、粘结助剂、触变助剂、抗裂助剂)及亚硝酸钙能够提高试样的抗折强度,对抗压强度提升作用有限;当磨细矿粉作为掺合料复合石灰后,抗压强度显著提高,综合抗压和抗折强度,最优配合比为60%石灰+40%矿粉+0.8%四种外加剂+2.0%亚硝酸钙,此时,抗折和抗压强度分别为1.44、13.90 MPa。

As a kind of traditional silicate building material, hydraulic lime is widely used in the restoration of historic build- ings of cultural relics. This paper studies the mineral powder and other admixtures modifying hydraulic lime mixture proportion op- timization design method, physical and mechanical properties,mechanism of hydration hardening. The researches show that：adding four additives （viscous agent, binder,thixotropic agent, anti-cracking agent） and calcium nitrite can improve the samples＇ flexural strength, but the compressive strength of ascension role is limited. However, when the mineral powder was used as admixture com- pound lime,compressive strength improved significantly. Combining compressive strength and flexnral strength,the flexural strength and compressive strength can reach 1.44 MPa and 13.90 MPa when adopted optimal mixture proportion of 60% lime,40% mineral powder,0.8% four additives,and 2.0% calcium nitrite.