發(fā)布時(shí)間：2018-04-09 23:03

  本文選題：堿骨料反應(yīng)　切入點(diǎn)：強(qiáng)度　出處：《西南交通大學(xué)》2015年碩士論文

【摘要】：本文結(jié)合貴廣鐵路堿骨料抑制試驗(yàn)課題,以建筑廢料——石粉的再生利用為背景,對石粉的粒徑及摻量對混凝土堿骨料反應(yīng)、強(qiáng)度及和易性的影響作了系統(tǒng)研究。從微觀角度分析堿骨料反應(yīng)的膨脹機(jī)理并建立數(shù)學(xué)模型描述堿骨料反應(yīng)膨脹過程,并提出以極限膨脹率為判斷堿骨料反應(yīng)程度的新思想。另外,對石粉對混凝土抗壓強(qiáng)度及流動(dòng)性的影響也作了系統(tǒng)描述,并分析其原因。主要研究內(nèi)容和成果如下：(1)結(jié)合不同摻量及不同粒徑石粉抑制混凝土堿骨料反應(yīng)的結(jié)果,以“最不利摻量”及“最不利粒徑”為基礎(chǔ),提出石粉“最有利摻量”及“最有利粒徑”且該“摻量”及“粒徑”對于不同配比混凝土有所不同。隨著石粉粒徑減小,混凝土堿骨料反應(yīng)先變強(qiáng),后變?nèi)?再變強(qiáng)；隨著石粉摻量增大,混凝土堿骨料反應(yīng)先變?nèi)?后變強(qiáng),再變?nèi)�。并建立微觀數(shù)學(xué)模型,解釋“最有利摻量”及“最有利粒徑”存在的原因。(2)對堿骨料反應(yīng)過程做出一定假設(shè),以微分方程及數(shù)理統(tǒng)計(jì)為理論基礎(chǔ),建立描述堿骨料反應(yīng)過程的數(shù)學(xué)模型,并預(yù)測快速砂漿棒法中齡期t→∞時(shí),試件的“極限膨脹率”,得出結(jié)論,石粉對堿骨料反應(yīng)的抑制主要存在于兩方面：降低試件最終膨脹率和降低堿骨料反應(yīng)速率。(3)無論石粉在混凝土中粒徑及摻量如何,在快速砂漿棒法42d齡期以內(nèi),各試件膨脹率差別不大,故建議對于摻入惰性摻合料的混凝土,摒棄以14d、28d膨脹率判斷堿骨料反應(yīng)極限膨脹率大小,若后續(xù)研究能找出ASR導(dǎo)致混凝土破壞時(shí)的極限膨脹率“閾值”,則可以“極限膨脹率”為依據(jù)判斷摻合料抑制堿骨料反應(yīng)的有效性。(4)石粉代替水泥會(huì)降低膠砂抗壓強(qiáng)度,石粉摻量對強(qiáng)度的影響遠(yuǎn)比粒徑的影響大,隨著石粉摻量增加,膠砂流動(dòng)性先變好后變差。膠砂強(qiáng)度及和易性不僅與石粉粒徑及摻量有關(guān),更與石粉及骨料級(jí)配有關(guān)。
[Abstract]:In this paper, the influence of particle size and content of stone powder on the reaction, strength and easiness of concrete alkali aggregate is studied systematically, based on the background of recycling and utilization of construction waste-stone powder in Gui-Guang Railway.The expansion mechanism of alkali aggregate reaction was analyzed from the microscopic point of view, and a mathematical model was established to describe the expansion process of alkali aggregate reaction. A new idea of judging the degree of alkali aggregate reaction with limit expansion rate was put forward.In addition, the influence of stone powder on the compressive strength and fluidity of concrete is also described systematically, and the reasons are analyzed.The main research contents and results are as follows: (1) combined with the results of inhibiting the reaction of concrete alkali aggregate with different amount of stone powder and different particle size, and based on "most unfavorable amount" and "most unfavorable particle size",It is pointed out that the most favorable amount of stone powder and the most favorable particle size are different for concrete with different proportions.With the decrease of stone particle size, the reaction of concrete alkali aggregate first becomes stronger, then weaker, and then stronger; with the increase of the content of stone powder, the reaction of concrete alkali aggregate first weakens, then becomes stronger, and then weakens.A microscopic mathematical model was established to explain the reasons for the existence of "most favorable dosage" and "most favorable particle size", and to make some assumptions about the reaction process of alkali aggregate, which was based on differential equation and mathematical statistics.A mathematical model describing the reaction process of alkali aggregate is established, and the "limit expansion rate" of the specimen is predicted when the intermediate age of the rapid mortar bar method is t 鈭，

本文編號(hào)：1728538