【摘要】：鋼纖維高強混凝土已廣泛應(yīng)用于水利及土木工程領(lǐng)域,其耐久性直接關(guān)系到結(jié)構(gòu)的使用性和安全性,所以鋼纖維混凝土的耐久性研究早已受到了國內(nèi)外研究界高度重視,但鋼纖維長徑比對其耐久性的影響研究較為不足,本文主要研究了鋼纖維長徑比對C60混凝土早期抗裂性能及抗凍性能的影響。本文研究的內(nèi)容主要有以下兩方面:(1)設(shè)計正交試驗,綜合分析水膠比、粉煤灰摻量和鋼纖維體積率等因素對C60混凝土 28d的抗壓強度、劈裂抗拉強度以及拉壓比三種力學性能的影響,主要結(jié)論如下:①鋼纖維對C60混凝土的抗壓強度、劈裂抗拉強度和拉壓比都有顯著影響,尤其對后兩者,但鋼纖維摻量過多又會對這三種性能產(chǎn)生削弱影響;②確定C60鋼纖維混凝土最佳配合方案為:水膠比取0.30,粉煤灰摻量取20%,鋼纖維體積率取1.50%。(2)基于最佳配合比,研究鋼纖維不同長徑比對C60混凝土早期抗裂性能、凍融前后力學性能和抗凍性能的影響,主要結(jié)論如下:①鋼纖維對C60混凝土早期裂縫有抑制作用,并且當鋼纖維長徑比為50時,C60混凝土早期塑性裂縫的面積和數(shù)量都被降到了最低,其阻裂效能等級達到一級;②C60鋼纖維混凝土的抗壓強度、劈裂抗拉強度和抗折強度,分別在鋼纖維長徑比為75、50和50時達到最大,綜合考慮下長徑比為50的鋼纖維對其力學性能增強效果最好;③鋼纖維長徑比對混凝土基體抗壓強度影響小于凍融次數(shù)對其影響;④當鋼纖維長徑比為50時,抗折和劈拉強度損失最小;長徑比為75時,其損失次之;未摻入鋼纖維和長徑比為25時,其損失最大;⑤長徑比為50和75的鋼纖維,對C60混凝土抗凍性有明顯的增強作用。本文探究了鋼纖維長徑比對C60混凝土力學性能和耐久性的影響,得出了抗裂性、抗凍性以及力學性能最好的C60鋼纖維混凝土配合方案為:水膠比取0.30,粉煤灰摻量取20%,鋼纖維體積率取1.50%,鋼纖維長徑比取50,并為建立鋼纖維混凝土抗凍性指標提供了理論依據(jù),也為試驗研究鋼纖維長徑比對高強混凝土耐久性的影響提供了借鑒和方向。
[Abstract]:Steel fiber high strength concrete has been widely used in the field of water conservancy and civil engineering, and its durability is directly related to the use and safety of the structure. Therefore, the durability research of steel fiber reinforced concrete has been attached great importance to at home and abroad. However, the influence of the aspect ratio of steel fiber on the durability of C60 concrete is not enough. This paper mainly studies the influence of the ratio of length to diameter on the early crack resistance and freezing resistance of C60 concrete. The main contents of this paper are as follows: (1) the orthogonal test is designed to analyze the compressive strength of C60 concrete for 28 days, including the ratio of water to binder, the content of fly ash and the volume ratio of steel fiber. The main conclusions are as follows: (1) Steel fiber has a significant effect on the compressive strength, splitting tensile strength and tensile compression ratio of C60 concrete, especially on the latter two. However, too much steel fiber will weaken these three properties. 2. The optimum mix scheme of C60 steel fiber reinforced concrete is determined as follows: water / binder ratio 0.30, fly ash content 20 and steel fiber volume ratio 1.50. (2) based on the optimum mix ratio, The effects of different aspect ratio of steel fiber on early crack resistance, mechanical properties and frost resistance of C60 concrete before and after freezing and thawing are studied. The main conclusions are as follows: 1 Steel fiber can inhibit early crack of C60 concrete. When the ratio of steel fiber aspect to diameter is 50, the area and number of early plastic cracks of C60 concrete are reduced to the lowest, and the grade of crack resistance effectiveness reaches the first grade. The compressive strength, splitting tensile strength and flexural strength of 2C60 steel fiber concrete are maximum when the aspect ratio of steel fiber is 75 ~ 50 and 50, respectively. (3) the influence of the ratio of length to diameter of steel fiber on the compressive strength of concrete matrix is less than that of freeze-thaw ratio, 4 when the ratio of length to diameter of steel fiber is 50, the loss of flexural and split tensile strength is the least, and the loss is second when the ratio of length to diameter is 75. When the ratio of steel fiber to diameter is 25, the loss of steel fiber is the biggest, and the freezing resistance of C60 concrete is enhanced obviously when the ratio of length to diameter is 50 and 75. In this paper, the influence of the ratio of length to diameter of steel fiber on mechanical properties and durability of C60 concrete is studied. The best fit scheme of C60 steel fiber concrete with crack resistance, frost resistance and mechanical properties is obtained as follows: water / binder ratio is 0.30, fly ash content is 20 percent. The volume ratio of steel fiber is 1.50 and the ratio of length to diameter of steel fiber is 50. It provides a theoretical basis for the establishment of freezing resistance index of steel fiber concrete, and also provides a reference and direction for the experimental study on the influence of steel fiber length to diameter ratio on the durability of high strength concrete.
【學位授予單位】：寧夏大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TU528

【參考文獻】

相關(guān)期刊論文 前10條

1 張偉;;鋼纖維聚合物混凝土的界面應(yīng)力傳遞與增強機理研究[J];山東農(nóng)業(yè)大學學報(自然科學版);2015年06期

2 徐禮華;陳平;黃樂;張奧利;李彪;;鋼-聚丙烯混雜纖維混凝土與變形鋼筋黏結(jié)性能試驗研究[J];土木工程學報;2015年04期

3 張麗哲;丁春奎;季濤;;聚丙烯粗纖維增強水泥基復合材料的抗裂性能[J];上海紡織科技;2015年01期

4 李川川;孫麗萍;朱海堂;張啟明;;鋼纖維對混凝土劈拉強度的影響研究[J];河北工業(yè)大學學報;2014年06期

5 王仁龍;張啟明;朱海堂;高丹盈;;鋼纖維混凝土抗折強度的影響因素分析[J];河北工業(yè)大學學報;2014年06期

6 蹇守衛(wèi);孔維;馬保國;張呂東;;纖維對薄層砂漿早期塑性收縮的影響[J];材料導報;2014年22期

7 徐禮華;梅國棟;黃樂;魯維妙;;鋼-聚丙烯混雜纖維混凝土軸心受拉應(yīng)力-應(yīng)變關(guān)系研究[J];土木工程學報;2014年07期

8 詹冬;金寶宏;;聚丙烯纖維混凝土抗壓強度與收縮性能時變規(guī)律研究[J];寧夏工程技術(shù);2014年02期

9 倪坤;宋中南;石云興;張燕剛;張濤;劉偉;;鋼纖維對混雜纖維混凝土抗彎性能的影響研究[J];施工技術(shù);2014年09期

10 夏冬桃;周博儒;劉向坤;楊應(yīng)平;;低摻量三元混雜纖維混凝土軸拉性能試驗[J];華中科技大學學報(自然科學版);2013年11期

，

本文編號：2313637