低收缩地质聚合物混凝土的配制及在海堤工程中的应用研究

Fabrication of Low-shrinkage Geological Polymer Concrete and Its Application in Seawall Engineering

摘要:

为了研究如何应对海洋环境下建筑物的损伤问题，以广东省某海堤为研究对象，将菱镁石煅烧制备成三种不同活性的MgO，再将不同活性的MgO进行搭配，与地质聚合物胶凝材料均匀混合制备成低收缩地质聚合物混凝土。然后基于标准测试方法测量其不同龄期的自收缩，利用万能试验机获得其不同龄期的力学性能，重点关注了补偿收缩后的低收缩地质聚合物混凝土的服役性能、抗压强度、混凝土内部温升与应变等指标对施工效果的影响。研究结果表明：补偿体积收缩后，地质聚合物混凝土自收缩大幅降低；地质聚合物混凝土相对普通混凝土而言，快硬、早强的特点更适合处于潮汐水位海堤的快速施工；与普通水泥混凝土相比，地质聚合物混凝土温升和内外温差均较小，开裂风险较低。因此，将低收缩地质聚合物混凝土应用在海堤工程中有重要的研究价值，其可替代普通混凝土以达到更好的施工效果。

Abstract:

In order to reduce the damage of buildings in the marine environment， magnesite was calcined into three types of MgO with different chemical activities， which were evenly mixed with geological polymer gel materials to form low-shrinkage geological polymer concretes. Then， the shrinkage properties of different geological polymer concretes were measured based on the standard testing method. The mechanical properties of different geological polymer concretes were tested by the universal testing machine. The influence of the compressive strength， internal temperature rise and strain of the low-shrinkage geological polymer concretes on the construction effectiveness were studied in detail. The results showed that the self-shrinkage of the geological polymer concrete was greatly reduced after the shrinkage compensation. Besides， geological polymer concrete is more suitable for rapid construction of seawalls compared with the ordinary cement concrete， which is due to the temperature rise and temperature difference of the geological polymer concrete are smaller， and cracking risk is lower. Therefore， it is important to study the applications of low-shrinkage geological polymer concretes in seawalls， which can replace ordinary concrete to achieve better construction results.