發(fā)布時(shí)間：2018-04-09 19:51

  本文選題：混凝土　切入點(diǎn)：硫酸鹽侵蝕　出處：《華北理工大學(xué)》2017年碩士論文

【摘要】：硫酸鹽侵蝕與高溫會(huì)造成混凝土的膨脹開裂及強(qiáng)度降低。已有研究表明使用鋁酸鹽水泥作為膠凝材料的混凝土具有較好的抗硫酸鹽侵蝕性能,采用燒結(jié)鋁礬土、氧化鋁陶瓷等耐磨骨料,可配制出高性能高耐磨的混凝土,但是不同摻合料對鋁酸鹽水泥水化產(chǎn)物在高溫下的晶型轉(zhuǎn)變以及對混凝土抗蝕耐磨性的影響尚未清楚。實(shí)驗(yàn)中重點(diǎn)研究了鋁酸鹽水泥體系、土聚水泥體系混凝土高溫條件下的抗蝕耐磨性。參照GB/T17671-1999,制備砂漿試塊,并將試塊分別放置于標(biāo)準(zhǔn)養(yǎng)護(hù)室、80℃水中、80℃5%的Na2SO4溶液中養(yǎng)護(hù),以質(zhì)量損失率、抗壓、抗折強(qiáng)度和耐磨度作為評判準(zhǔn)則,研究膠凝材料體系、骨料、養(yǎng)護(hù)環(huán)境對混凝土抗硫酸鹽侵蝕與耐磨性的影響。采用X射線衍射(XRD)、掃描電子顯微鏡(SEM)研究混凝土中硫酸鹽侵蝕的反應(yīng)產(chǎn)物和微觀結(jié)構(gòu)。研究結(jié)果表明:使用燒鋁礬土砂作骨料的鋁酸鹽水泥混凝土抗折強(qiáng)度、抗壓強(qiáng)度、耐磨度都普遍高于使用標(biāo)準(zhǔn)砂的鋁酸鹽水泥混凝土,摻入三聚磷酸鈉后,混凝土的強(qiáng)度和耐磨度都有明顯下降;試塊的強(qiáng)度越高,耐磨度越高。80℃的高溫條件有助于土聚水泥的堿激發(fā)反應(yīng)進(jìn)行,在80℃水中養(yǎng)護(hù)的試塊性能顯著高于標(biāo)準(zhǔn)養(yǎng)護(hù)和80℃硫酸鈉溶液中養(yǎng)護(hù)的2組。土聚水泥在高溫下的抗硫酸鹽侵蝕性能良好。通過微觀分析,發(fā)現(xiàn)三聚磷酸鈉對鋁酸鹽水泥水化的最終產(chǎn)物無明顯影響,結(jié)合水化熱分析與強(qiáng)度測試結(jié)果,摻5%的三聚磷酸鈉會(huì)大量放熱,促進(jìn)鋁酸鹽水泥早期水化產(chǎn)物CAH_(10)與C_2AH_8轉(zhuǎn)變?yōu)镃_3AH_6,使混凝土強(qiáng)度降低。骨料中的高鋁礦物能有效提高鋁酸鹽水泥混凝土抗硫酸鹽侵蝕性能。
[Abstract]:Sulfate erosion and high temperature will cause expansion cracking and strength reduction of concrete.It has been shown that the concrete with aluminate cement as the cementitious material has better resistance to sulfate erosion, and the high performance and high wear resistant concrete can be prepared by using sintered bauxite, alumina ceramic and other wear-resistant aggregates.However, the effects of different admixtures on the crystalline transformation of aluminate cement hydration products at high temperature and on the corrosion and wear resistance of concrete are not clear.In the experiment, the corrosion and wear resistance of aluminate cement system and soil-aggregate cement system concrete at high temperature were studied.Effect of curing Environment on Sulfate Resistance and Wear Resistance of concrete.The reaction products and microstructure of sulfate erosion in concrete were studied by means of X-ray diffraction and scanning electron microscopy (SEM).The results show that the flexural strength, compressive strength and wear resistance of aluminate cement concrete with bauxite sand as aggregate are generally higher than that of aluminate cement concrete with standard sand.The strength and wear resistance of concrete are obviously decreased, and the higher the strength of the test block, the higher the wear resistance. 80 鈩，

本文編號：1727890