本文選題：堿骨料反應(yīng) + 巖相法��； 參考：《新疆農(nóng)業(yè)大學(xué)》2015年碩士論文

【摘要】：混凝土堿骨料反應(yīng)是影響混凝土耐久性的重要因素之一,本文通過(guò)快速砂漿棒法和棱柱體法試驗(yàn)研究了摻合料摻量及水膠比對(duì)試件膨脹率的影響及抑制堿骨料反應(yīng)的能力,得到的主要結(jié)論如下:(1)通過(guò)巖相法試驗(yàn)確定,烏魯木齊地區(qū)混凝土所用骨料67%為凝灰?guī)r,用快速砂漿棒法和棱柱體法測(cè)得膨脹率都超過(guò)規(guī)范要求,均能判定凝灰?guī)r為堿活性骨料。(2)通過(guò)快速砂漿棒法和棱柱體試驗(yàn)研究,抑制堿骨料反應(yīng)的主要因素是水膠比、摻合料和養(yǎng)護(hù)齡期。同齡期混凝土試件的膨脹率,隨水膠比降低或摻合料摻量增加而降低,隨著養(yǎng)護(hù)齡期的延長(zhǎng),混凝土試件的膨脹率逐漸增長(zhǎng)。從配合比的角度來(lái)看,除了考慮堿含量以外,一方面,通過(guò)降低水膠比來(lái)增加混凝土的密實(shí)度,能降低混凝土中水分的移動(dòng)和堿離子的移動(dòng);另一方面,摻加的礦物摻合料屬于活性混合材料,活性成分與水泥熟料的水化產(chǎn)物氫氧化鈣和水在有堿的情況下能夠發(fā)生反應(yīng),生成水硬性物質(zhì)。摻合料之所以能夠抑制堿骨料反應(yīng),就是因?yàn)槠湮樟怂嗷蛘呋炷林械膲A,降低了混凝土中的堿含量,可以有效地起到抑制堿骨料反應(yīng)的作用。其次,摻合料可以等量去取代水泥,水泥用量少了,混凝土中的堿含量也會(huì)相應(yīng)地減低,也就等于降低了混凝土中的堿。(3)通過(guò)試驗(yàn)研究發(fā)現(xiàn)一種現(xiàn)象,摻加摻和料的棱柱體法試件52周齡期內(nèi)膨脹率受水膠比影響較小,0.44水膠比試件膨脹率低于低水膠比試件的膨脹率。按照高性能混凝土強(qiáng)度規(guī)律分析,0.44水膠比的試件密實(shí)度遠(yuǎn)低于0.40以下水膠比的試件,試件內(nèi)部的孔隙率遠(yuǎn)大于、多余低水膠比試件。因此,這種現(xiàn)象可能是應(yīng)大水膠比試件中的孔隙抵消了部分骨料界面發(fā)生堿骨料膨脹的應(yīng)力,才造成0.44水膠比試件未有明顯的膨脹率增長(zhǎng),望在以后研究中能得到進(jìn)一步的驗(yàn)證。
[Abstract]:The alkali aggregate reaction of concrete is one of the important factors affecting the durability of concrete. In this paper, the influence of admixture content and water / binder ratio on the expansion rate of the specimen and the ability to restrain the reaction of alkali aggregate are studied by means of rapid mortar bar method and prism method. The main conclusions are as follows: (1) through lithofacies test, 67% of aggregate used in Urumqi concrete is tuff, and the expansion rate measured by rapid mortar bar method and prism method is above the standard requirement. Through rapid mortar bar method and prism test, the main factors of inhibiting alkali aggregate reaction are water-binder ratio, admixture and curing age. The expansion rate of concrete specimens at the same age decreases with the decrease of water-binder ratio or with the increase of admixture content. With the extension of curing age, the expansion rate of concrete specimens increases gradually. From the point of view of mix ratio, besides considering the alkali content, on the one hand, by reducing the water-binder ratio to increase the compactness of concrete, the movement of water and alkali ions in concrete can be reduced; on the other hand, The mineral admixture is a kind of active mixing material. The active component can react with the hydration product of cement clinker calcium hydroxide and water in the presence of alkali to form a hydrated substance. The reason why admixture can inhibit alkali aggregate reaction is that it absorbs alkali in cement or concrete, reduces alkali content in concrete, and can effectively inhibit alkali aggregate reaction. Secondly, the admixture can replace cement by the same amount. When the amount of cement is reduced, the alkali content in concrete will be reduced accordingly, which is equivalent to reducing the alkali content in concrete. The swelling ratio of prism specimen with admixture was less affected by water-binder ratio in 52 weeks than that of low water-gel ratio. According to the strength law of high performance concrete, the compactness of the specimen with 0.44 water-binder ratio is far lower than that of the water-binder ratio below 0.40, and the internal porosity of the specimen is much larger than that of the low water-binder ratio. Therefore, this phenomenon may be due to the fact that the pores in the water / binder ratio specimens offset the stress of alkali aggregate expansion at the interface of some aggregates, resulting in no obvious increase in the expansion rate of 0.44 water-gel ratio specimens. It is hoped that further verification will be made in future studies.
【學(xué)位授予單位】：新疆農(nóng)業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TU528

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相關(guān)期刊論文 前3條

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本文編號(hào)：1944229