發(fā)布時間：2018-05-14 07:19

  本文選題：硫鋁酸鹽水泥 + 低成本��； 參考：《武漢理工大學》2015年碩士論文

【摘要】：硫鋁酸鹽水泥具有凝結(jié)時間短、早強高強、高抗?jié)B、良好耐久性等優(yōu)點,基于原材料的限制,硫鋁酸鹽水泥成本較硅酸鹽水泥高,凝結(jié)時間不易控制,摻合料引入到硫鋁酸鹽水泥中易降低其力學、抗?jié)B等性能,限制了其推廣使用。論文依托國家自然科學基金項目(51178363),通過大摻量引入礦物摻合料(粉煤灰、礦粉),降低硫鋁酸鹽水泥的成本,使其達到一定的經(jīng)濟效益(摻合料摻量達40%),研究不同摻合料對硫鋁酸鹽水泥基本工作性能、力學性能、干縮的影響。根據(jù)化學激發(fā)效應(yīng)、超細粉體效應(yīng)、結(jié)晶誘導(dǎo)效應(yīng)、外加劑調(diào)節(jié)、優(yōu)勢互補原理等對低成本硫鋁酸鹽水泥基膠凝材料進行改性,綜合考慮基本工作性能、力學性能、微觀性能、耐久性能等,調(diào)配出最佳改性配比,使體系成本降低的同時,性能得到提高。其中,化學激發(fā)是最重要的改性方法,論文中把抗壓強度作為改性效果最重要指標。主要研究結(jié)果如下:1、礦粉、硅灰對硫鋁酸鹽水泥凝結(jié)時間作用效果較小,粉煤灰具有一定的緩凝作用;粉煤灰與礦粉對硫鋁酸鹽水泥的標稠用水量及流動度具有積極作用,硅灰摻量少于5%時,具有積極作用;引入粉煤灰與礦粉后,硫鋁酸鹽水泥各齡期抗折、抗壓強度均降低,當硅灰摻量不超過5%時,對抗壓強度具有促進作用;三種摻合料對硫鋁酸鹽水泥的干縮均具有明顯的抑制作用。2、篩選出一種改性效果較好的堿性激發(fā)劑M,引入M后,體系2h、3d、7d、28d、1年抗壓強度最高分別提高了134%、93%、62%、61%、63%。M促進了硫鋁酸鹽水泥體系早期鈣礬石及凝膠的生成,使其具有較高的早期強度,激發(fā)了粉煤灰的活性,使其參與水泥的后續(xù)水化,提高了漿體密實度。M可能易使鈣礬石早期結(jié)晶程度變差,當累積至7d時,易出現(xiàn)強度倒縮,隨養(yǎng)護時間延長,這種現(xiàn)象消失。3、與體系相容性排序依次是聚羧酸KH-5減水劑KH-6減水劑氨基磺酸系減水劑萘系減水劑。對粉煤灰-硫鋁酸鹽水泥體系強度影響排序依次是納米二氧化硅(1%-2%)超細碳酸鈣(1%-3%)硅灰(≤10%),正交試驗表明對礦粉-粉煤灰-硫鋁酸鹽水泥強度影響排序依次是激發(fā)劑硅灰超細碳酸鈣,最佳摻量分別為4%、6%、3%。4、礦粉與粉煤灰以2:1復(fù)合比單摻粉煤灰的效果好,體系2h、3d、7d、28d、90d抗壓強度分別提高7%、16%、23.7%、20%、40%;確定最佳組分及改性配比后,粉煤灰組2h、3d、7d、28d、90d抗壓強度分別提高了17.5%、42.8%、51.8%、61.0%、66.7%,礦粉與粉煤灰復(fù)合組分別提高了12.3%、14.8%、13.8%、26%、15.4%。在20%濃度硫酸鈉、20%濃度氯化鈉溶液中侵蝕90d后,各組抗壓強度不但沒有降低,反而有不同程度的提高,礦粉-粉煤灰-硫鋁酸鹽水泥組提高的最明顯。
[Abstract]:Sulphoaluminate cement has the advantages of short setting time, early strength and high strength, high impermeability, good durability and so on. Due to the limitation of raw materials, the cost of sulphoaluminate cement is higher than that of Portland cement, and the setting time is not easy to control. It is easy to reduce mechanical and impermeable properties of sulphoaluminate cement by introducing admixture, which limits its popularization and application. Based on the project of National Natural Science Foundation of China 51178363, the paper introduces mineral admixture (fly ash, mineral powder) to reduce the cost of sulphoaluminate cement by introducing large amount of mineral admixture (fly ash, mineral powder). The effects of different admixtures on the basic working properties, mechanical properties and dry shrinkage of sulphoaluminate cement were studied. According to the chemical excitation effect, ultrafine powder effect, crystallization induction effect, admixture adjustment, advantage complementary principle and so on, the low cost sulphoaluminate cement based cementitious materials were modified, and the basic working properties, mechanical properties and microscopic properties were considered synthetically. The best ratio of modification was prepared, so that the cost of the system was reduced, and the performance was improved at the same time. Among them, chemical excitation is the most important modification method, and the compressive strength is regarded as the most important index of modification effect in this paper. The main results are as follows: (1) the effect of mineral powder and silica fume on the setting time of sulphoaluminate cement is small, the fly ash has a certain retarding effect, and the fly ash and mineral powder have a positive effect on the standard water consumption and fluidity of sulphoaluminate cement. When the amount of silica fume is less than 5, it has a positive effect, when fly ash and mineral powder are introduced, the compressive strength of sulphoaluminate cement decreases in every age, and when the amount of silica fume is less than 5, it can promote the compressive strength of sulphoaluminate cement. The dry shrinkage of sulphoaluminate cement was inhibited obviously by the three admixtures. The maximum compressive strength of the system was 134kW / 62and 62D / 28d, respectively, which promoted the formation of ettringite and gel in the early stage of sulphoaluminate cement system, made it have higher early strength, stimulated the activity of fly ash, and made it participate in the subsequent hydration of cement. The increase of slurry compactness. M may make the early crystallization degree of ettringite worse, and when it accumulates to 7 days, the strength will shrink easily, and the curing time will be prolonged. The order of compatibility with the system is polycarboxylic acid KH-5 water reducer, KH-6 water reducer, amino sulfonic acid superplasticizer, naphthalene series water reducer. The order of influence on the strength of fly ash-sulphoaluminate cement system is nanometer silica 1- 2) ultrafine calcium carbonate and 1-3) silica fume (鈮，

本文編號：1886897