【摘要】：煤矸石是在煤礦開采、洗煤與選煤過(guò)程中排出的工業(yè)固體廢棄物,當(dāng)藏匿在煤矸石中的可燃物在大自然中自燃后就形成了自燃煤矸石。以自燃煤矸石為基材進(jìn)行磨細(xì)加工,達(dá)到一定細(xì)度可制備粉體材料—自燃煤矸石粉。本文針對(duì)國(guó)內(nèi)突顯出的優(yōu)質(zhì)混凝土摻合料短缺現(xiàn)狀,依托國(guó)家自然基金委員會(huì)與神華集團(tuán)有限公司聯(lián)合資助項(xiàng)目(U1261122),研究自燃煤矸石粉作為混凝土摻合料的可行性以及對(duì)混凝土性能的影響,試圖開發(fā)新品種混凝土摻合料,探索自燃煤矸石資源化應(yīng)用的新途徑。本文首先采用機(jī)械活化的方法,激發(fā)自燃煤矸石活性,根據(jù)自燃煤矸石粉-水泥膠砂流動(dòng)度和強(qiáng)度試驗(yàn)結(jié)果,以及粉磨能耗確定自燃煤矸石的經(jīng)濟(jì)粉磨時(shí)間；在此基礎(chǔ)上,選擇自燃煤矸石粉摻量、減水劑品種和摻量三個(gè)影響因素,通過(guò)混凝土稠度和強(qiáng)度的正交試驗(yàn),研究自燃煤矸石粉與減水劑的相容性問(wèn)題；最后,以自燃煤矸石粉為摻合料配制混凝土,研究自燃煤矸石粉摻量對(duì)混凝土抗氯離子滲透和抗凍融性能的影響,為自燃煤矸石粉礦物摻合料的工程應(yīng)用提供基礎(chǔ)保證。本文得出如下結(jié)論：(1)阜新清河門礦自燃煤矸石易磨指數(shù)較高,粉磨時(shí)間為4-6min時(shí),其活性指數(shù)大于Ⅰ級(jí)粉煤灰,但稍遜S95礦粉及水泥,膠砂流動(dòng)度介于粉煤灰與礦粉之間,滿足作為混凝土礦物摻合料的基本要求。(2)自燃煤矸石粉摻合料與不同品種減水劑復(fù)合雙摻時(shí),相容性是不同的,相容程度為：聚羧酸系萘系木質(zhì)素系。其中自燃煤矸石粉與聚羧酸減水劑雙摻時(shí)更能表現(xiàn)出優(yōu)異的相容性能。(3)比較不同自燃煤矸石粉摻量、不同品種減水劑和摻量的混凝土稠度和強(qiáng)度規(guī)律時(shí)發(fā)現(xiàn),自燃煤矸石粉摻量對(duì)拌合物粘聚性和保水性有一定程度的改善,對(duì)初始坍落度及經(jīng)時(shí)損失影響不明顯,但與萘系減水劑雙摻時(shí)對(duì)混凝土7d抗壓強(qiáng)度有一定影響,特別是后期強(qiáng)度增長(zhǎng)幅度比純水泥混凝土大；減水劑的品種和摻量對(duì)自燃煤矸石粉摻合料混凝土的工作性和強(qiáng)度影響都不明顯。(4)自燃煤矸石粉少量摻入,雖然降低了混凝土的前期強(qiáng)度,但有利于混凝土的后期強(qiáng)度發(fā)展及耐久性能的提高。自燃煤矸石粉的摻入減少了硬化體中有害孔的含量,固化了侵入體系中的氯離子,摻量為35%時(shí),60d齡期的混凝土氯離子滲透等級(jí)達(dá)到“極低”標(biāo)準(zhǔn)；自燃煤矸石粉摻量為15%時(shí),混凝土的抗凍等級(jí)超過(guò)Fi200。只要控制好水膠比,保證混凝土具有較高的致密性,即使煤矸石摻合料的摻量較大,也能獲得較高的強(qiáng)度和較好的抗凍性。
[Abstract]:Coal gangue is the industrial solid waste discharged in the process of coal mining, coal washing and coal preparation. When the combustible substance hidden in the coal gangue spontaneously burns in nature, it forms spontaneous combustion gangue. Spontaneous combustion gangue powder can be prepared by grinding coal gangue with certain fineness. In view of the shortage of high quality concrete admixture in China, this paper relies on the joint funded project (U1261122) by the National Natural Fund Committee and Shenhua Group Co., Ltd. The feasibility of spontaneous combustion coal gangue powder as concrete admixture and its influence on concrete performance are studied. The author tries to develop new concrete admixture and to explore a new way for the application of spontaneous combustion coal gangue. In this paper, the method of mechanical activation is used to stimulate the activity of spontaneous combustion coal gangue. The economic grinding time of spontaneous combustion coal gangue is determined according to the test results of flowability and strength of spontaneous combustion coal gangue powder and cement sand, and the energy consumption of grinding. On this basis, the compatibility of spontaneous combustion coal gangue powder and water reducer is studied by orthogonal test of consistency and strength of concrete. Finally, the effect of the content of spontaneous combustion coal gangue powder on the resistance to chloride ion permeation and freeze-thaw resistance of concrete is studied, which provides the basic guarantee for the engineering application of the mineral admixture of spontaneous combustion coal gangue powder. The conclusions are as follows: (1) when the grinding time is 4-6min, the activity index of spontaneous combustion gangue in Fuxin Qinghemen Mine is higher than that of Grade 鈪，

本文編號(hào)：2414291