本文選題：大骨料混凝土 + 凍融循環(huán)　； 參考：《大連交通大學》2015年碩士論文

【摘要】：大骨料混凝土主要用于建造水工結(jié)構(gòu)物,如水工大壩、水閘、船塢等。凍害是影響水工結(jié)構(gòu)物耐久性的重要因素。另外,在水工結(jié)構(gòu)物非線性分析中,要充分考慮混凝土所處的應(yīng)力狀態(tài)及其所受荷載的加載速率影響,因為在使用過程中,水工結(jié)構(gòu)物中的混凝土多處于雙軸和三軸等復雜受力狀態(tài),且一般狀態(tài)下混凝土所受到的荷載的加載速率通常小于10-5/s,而在地震狀況下,其所受加載速率一般在10-4/s~10-2/s動態(tài)加載范圍內(nèi)。許多學者對大骨料混凝土的力學性能進行了試驗研究,主要有單軸應(yīng)力狀態(tài)下的靜態(tài)、動態(tài)試驗研究,雙軸、三軸應(yīng)力狀態(tài)下的靜態(tài)試驗研究,但研究多為濕篩混凝土。關(guān)于大骨料混凝土的多軸動態(tài)試驗研究則較少,并且均未考慮凍融循環(huán)作用的影響。本文依托清華大學水沙科學與水利水電工程國家重點實驗室開放研究基金資助課題——凍融后水工混凝土多軸動態(tài)強度及破壞機理研究,對大骨料混凝土進行了凍融循環(huán)后動態(tài)雙軸受壓及常態(tài)下動態(tài)雙軸拉壓性能試驗研究,具體研究內(nèi)容及結(jié)論如下:(1)對大骨料混凝土立方體試件進行了凍融循環(huán)試驗及動態(tài)雙軸壓縮試驗,實測了大骨料混凝土經(jīng)歷不同凍融循環(huán)次數(shù)后的質(zhì)量損失、損傷形態(tài),以及不同應(yīng)力比和應(yīng)變速率下的破壞形態(tài)、極限強度、應(yīng)力-應(yīng)變關(guān)系曲線。根據(jù)試驗數(shù)據(jù)分析了極限強度和變形性能與凍融循環(huán)次數(shù)、應(yīng)力比以及應(yīng)變速率的關(guān)系,分別在主應(yīng)力空間和八面體應(yīng)力空間建立了凍融循環(huán)后大骨料混凝土動態(tài)雙軸壓應(yīng)力狀態(tài)下的破壞準則。(2)對常態(tài)下大骨料混凝土棱柱體試件進行了動態(tài)雙軸拉壓試驗,實測了不同拉壓比和應(yīng)變速率下大骨料混凝土的破壞形態(tài)、極限強度和應(yīng)力-應(yīng)變關(guān)系曲線。根據(jù)試驗數(shù)據(jù)分析了極限強度和變形性能與拉壓比和應(yīng)變速率的關(guān)系,分別在主應(yīng)力空間和八面體應(yīng)力空間建立了大骨料混凝土動態(tài)雙軸拉壓應(yīng)力狀態(tài)下的破壞準則。(3)將不同學者對普通混凝土、濕篩混凝土、引氣混凝土的雙軸極限強度和破壞準則研究成果與本文的試驗結(jié)果進行對比分析。分析結(jié)果表明,大骨料混凝土單軸和雙軸抗壓強度基本為濕篩混凝土抗壓強度的0.7~0.8倍。大骨料混凝土雙軸較單軸抗壓強度提高幅度小于濕篩混凝土。各類混凝土單軸抗壓強度隨應(yīng)變速率提高的幅度均大于雙軸抗壓強度。凍融循環(huán)作用后,普通混凝土與大骨料混凝土雙軸抗壓強度損失率小于單軸抗壓強度損失率。靜、動態(tài)雙軸拉壓破壞準則可用直線或二次曲線形式表達。
[Abstract]:Large aggregate concrete is mainly used to build hydraulic structures, such as hydraulic dams, locks, docks, etc. Freezing injury is an important factor affecting the durability of hydraulic structures. In addition, in nonlinear analysis of hydraulic structures, due consideration should be given to the stress state of concrete and the effect of loading rate on the load, because in the process of use, The concrete in hydraulic structures is usually in biaxial and triaxial states, and the loading rate of concrete is usually less than 10 ~ (-5) / s in general state, but in earthquake, the loading rate of concrete is usually less than 10 ~ (-5) / s. The loading rate is generally within the range of dynamic loading of 10-4/s~10-2/s. Many scholars have done experimental research on the mechanical properties of large aggregate concrete, including static, dynamic, biaxial and triaxial stress state, but mostly wet sieve concrete. There are few multiaxial dynamic tests on large aggregate concrete, and the effect of freeze-thaw cycle is not taken into account. Based on the open research fund of the State key Laboratory of Water and sediment Science and Water Conservancy and Hydropower Engineering of Tsinghua University, the research on the multiaxial dynamic strength and failure mechanism of freeze-thawed hydraulic concrete is carried out in this paper. The dynamic biaxial compression behavior of large aggregate concrete under freezing and thawing cycles and the dynamic biaxial tension and compression properties under normal condition were studied. The specific research contents and conclusions are as follows: (1) Freeze-thaw cycle test and dynamic biaxial compression test are carried out on cube specimens of large aggregate concrete. The mass loss and damage form of large aggregate concrete after different freeze-thaw cycles are measured. The failure patterns, ultimate strength and stress-strain curves of different stress ratios and strain rates are also discussed. Based on the experimental data, the relationship between ultimate strength and deformation performance and the number of freeze-thaw cycles, stress ratio and strain rate is analyzed. In the principal stress space and octahedron stress space, the failure criteria of large aggregate concrete under dynamic biaxial compression stress were established respectively. (2) the dynamic biaxial tensile compression tests were carried out on the prism specimens of large aggregate concrete under normal condition. The failure patterns, ultimate strength and stress-strain relationship curves of large aggregate concrete under different tension and compression ratios and strain rates were measured. Based on the experimental data, the relationship between ultimate strength and deformation performance, tensile compression ratio and strain rate is analyzed. In the principal stress space and octahedron stress space respectively, the failure criteria of large aggregate concrete under dynamic biaxial tension and compression stress are established. (3) different scholars are applied to ordinary concrete and wet screen concrete. The research results of biaxial ultimate strength and failure criterion of air-entrained concrete are compared with the experimental results in this paper. The results show that the uniaxial and biaxial compressive strength of large aggregate concrete is 0.7 ~ 0.8 times of that of wet screen concrete. The biaxial compressive strength of large aggregate concrete is smaller than that of wet screen concrete. The increase of uniaxial compressive strength with strain rate is greater than that of biaxial compressive strength. After freeze-thaw cycle, the loss rate of biaxial compressive strength of ordinary concrete and large aggregate concrete is lower than that of uniaxial compressive strength. Static and dynamic biaxial tension-compression failure criteria can be expressed in the form of straight lines or conic curves.
【學位授予單位】：大連交通大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TU528

【相似文獻】

相關(guān)期刊論文 前10條

1 姚志玉;劉永奎;張冬原;;自密實混合骨料混凝土優(yōu)化配制及性能研究[J];商品混凝土;2012年04期

2 許賢敏;;預(yù)填骨料混凝土[J];建筑工人;1995年04期

3 王磊;趙艷林;呂海波;;珊瑚骨料混凝土的基礎(chǔ)性能及研究應(yīng)用前景[J];混凝土;2012年02期

4 劉志勇;;預(yù)填骨料混凝土在惠生出運碼頭工程中的應(yīng)用[J];邯鄲職業(yè)技術(shù)學院學報;2013年02期

5 蘆超;李海軍;;鋼筋鋼絲網(wǎng)預(yù)填骨料混凝土復合加固方法討論[J];山西建筑;2013年36期

6 郭小平;;自密實混合骨料混凝土優(yōu)化配制及性能研究[J];江西建材;2013年05期

7 宋玉普;尹翠;沈璐;;大骨料混凝土在動態(tài)雙軸壓應(yīng)力下的試驗研究[J];混凝土;2013年10期

8 張寶生;孔麗娟;袁杰;葛勇;;輕骨料預(yù)濕程度對混合骨料混凝土力學性能的影響[J];混凝土;2006年10期

9 高振國;羅永會;耿辰曉;;膨潤土對預(yù)填骨料混凝土性能的影響[J];石家莊鐵道學院學報;2006年01期

10 王武祥;;粉煤灰改性再生廢磚骨料混凝土性能的研究[J];建筑砌塊與砌塊建筑;2007年01期

相關(guān)會議論文 前8條

1 v繅，

本文編號：2057109