【正文】 工程應(yīng)用實踐表明，補償收縮混凝土具有優(yōu)異的抗裂防滲性能，是理想的混凝土結(jié)構(gòu)自防水材料，地下建筑物使用補償收縮混 凝土，完全可以取消外防水，不但縮短了建設(shè)工期，而且節(jié)約了工程造價，防水年限也與建筑物等壽。由于再生混凝土彈性模量較低，導(dǎo)致脆性降低，韌性增大，預(yù)計對再生混凝土結(jié)構(gòu)的抗震性能有利，并增強其抵抗動荷載的能力。 . 干燥收縮與普通混凝土一樣，補償收縮混凝土在空氣中同樣會發(fā)生干燥收縮，影響其干燥收縮的因素也與普通混凝土大致相同，除了相對濕度這個外部因素，水膠比是比較重要的內(nèi)在因素。 3CaSO4面對砂石等自然資源日益短缺，而建筑廢棄物日漸增加的嚴峻形勢，各國政府和研究機構(gòu)紛紛制定政策，發(fā)展新技術(shù)，以促進建筑廢棄物尤其是舊混凝土的再生利用?；炷辽a(chǎn)需要大量的粗細骨料 — 砂石，隨著對砂石的不斷開采，天然建筑骨料趨于枯竭，開采成本高，對生態(tài)環(huán)境的 破壞也十分嚴重。 recycled concrete replaced natural coarse aggregate with recycled coarse aggregate strength decreased less, and regeneration concrete recycled fine aggregate instead of natural fine aggregate strength decreased obviously, the age showed the same trend。 recycled aggregate。 in addition, due to the hydration expansion hole filling effect of products, the large hole in cement paste is smaller, the total porosity, which can improve the pore structure of concrete, greatly improve the impermeability of concrete, therefore make shrinkage pensating concrete expansive cement in foreign countries is also known as the waterproof cement. The shrinkage pensating concrete is an important branch of modern concrete science, its unique properties, is to solve the volume stability, high performance concrete is an important technical basis to improve the durability of concrete, the research on it has yet to be further and perfect, this paper expounds some basic properties of shrinkage pensating concrete. Expansion agent Physical and chemical properties: refers to the concrete expansion agent in concrete mixing process and the cement, water mixing after hydration reaction of stringier [3CaO ? Al2O3 ? 3CaSO4 ? 32H2O] or calcium hydroxide [Ca (OH) 2], make concrete produce volume expansion admixture. Concrete expansion agent is used to prepare the expansive concrete (including shrinkage pensating concrete and self stressing concrete), shrinkage pensating concrete shrinkage and pacting concrete with, improve concrete anti permeability role pensation concrete, in civil engineering in two aspects mainly used for waterproofing and anti cracking, now use more occasions is preparation of high grade waterproof concrete and appropriate to extend the expansion joint or post cast band spacing. 4 Basic properties of shrinkage pensating concrete Material Concrete before hardening Agent content and fresh initial concrete slump expansion: expansion agent effect on the initial slump of fresh concrete degree, largely depends on the expansion agent fineness, when the expansion and cement fineness difference, mixing water demand is basically the same, almost has no effect on the initial slump. Setting time Effect of expansive agent on setting time of concrete expansion admixture added: no matter what, will make the concrete setting time, expansion admixture amount bigger, the setting time is fast, doping agent will have the same results with and without the addition. Curing conditions Compared with ordinary concrete, shrinkage pensating concrete need more water conservation fully, because the water is the essential factors of expansion, long in the water curing of concrete can obtain the biggest expansion.