本文關(guān)鍵詞： 廢棄混凝土 尺寸效應(yīng) 裂縫發(fā)展 再生混合墻 抗震性能　出處：《華南理工大學(xué)》2013年博士論文　論文類型：學(xué)位論文

【摘要】：再生骨料混凝土是廢棄混凝土循環(huán)利用的一條有效途徑，但再生骨料的生產(chǎn)過程較為繁瑣且能耗較大，，加之再生骨料混凝土的配制仍需耗費(fèi)大量水泥。為此，課題組提出了在結(jié)構(gòu)構(gòu)件中直接采用大尺度廢棄混凝土的思想，從而將廢棄混凝土的回收利用從骨料層次提升一至兩個數(shù)量級到達(dá)大尺度塊體或節(jié)段層次。課題組前期曾對采用大尺度廢棄混凝土塊體或節(jié)段的再生混合混凝土及其構(gòu)件性能進(jìn)行了初步研究，在此基礎(chǔ)上本文進(jìn)一步開展了再生混合混凝土受壓尺寸效應(yīng)以及外置薄鋼板再生混合墻抗震性能兩方面探討。 本文主要工作包括： 通過51個再生混合混凝土立方體試件和36個圓柱體試件的受壓試驗(yàn)，揭示了試件外形尺寸、廢棄混凝土塊體特征尺寸等因素對再生混合混凝土抗壓強(qiáng)度、彈性模量和峰值應(yīng)變的影響規(guī)律。研究表明：在特征比保持不變的情況下，再生混合混凝土組合抗壓強(qiáng)度隨試件外形尺寸的增大而減小，既符合尺寸效應(yīng)律也滿足修正的尺寸效應(yīng)律；在試件外形尺寸保持不變的情況下，組合抗壓強(qiáng)度隨特征比的增大而減小；建立的組合抗壓強(qiáng)度與特征比之間的定量關(guān)系與試驗(yàn)結(jié)果吻合良好；構(gòu)建的組合抗壓強(qiáng)度預(yù)測公式可同時考慮試件外形尺寸和廢棄混凝土塊體特征尺寸的變化且具有較好精度；試件外形尺寸和廢棄混凝土塊體特征尺寸對再生混合混凝土彈性模量和峰值應(yīng)變的影響有限。 利用數(shù)字圖像相關(guān)(Digital Image Correlation，簡稱DIC)測量技術(shù)對再生混合混凝土的受壓破壞過程進(jìn)行了揭示，研究表明：廢棄混凝土塊體與新混凝土之間的界面并未出現(xiàn)明顯的裂縫集聚萌發(fā)及擴(kuò)展現(xiàn)象，裂縫的后期發(fā)展多以貫穿新混凝土和廢棄混凝土塊體的方式進(jìn)行。 通過7片外置薄鋼板再生混合墻的擬靜力試驗(yàn)研究，分析了廢棄混凝土取代率、鋼板厚度、軸壓比、橫隔板間距、高寬比等參數(shù)對試件抗震性能的影響�；谛�、舊混凝土的組合強(qiáng)度，對試件的水平承載力進(jìn)行了近似計算分析，并在總用鋼量基本一致的情況下與鋼筋混凝土墻的水平承載力進(jìn)行了對比。研究表明：廢棄混凝土取代率在0～33%之間變化對試件的初始剛度、水平承載力、破壞位移角、耗能能力、滯回曲線形狀等抗震性能影響有限；外置薄鋼板再生混合墻的設(shè)計軸壓比不宜超過0.35；在墻厚與鋼板厚度之比高達(dá)120的情況下，外置薄鋼板再生混合墻仍具有較穩(wěn)定的滯回性能和變形能力，其破壞位移角滿足現(xiàn)行抗震規(guī)范要求；外置薄鋼板再生混合墻具有與鋼筋混凝土墻相當(dāng)甚至略高的耗能能力；在總用鋼量基本一致的情況下，外置薄鋼板再生混合墻具有與鋼筋混凝土墻基本相當(dāng)?shù)乃匠休d力。 采用ABAQUS通用軟件，建立了外置薄鋼板再生混合墻的有限元模型，考察了主要參數(shù)對該類構(gòu)件水平力—水平位移曲線的影響，并與試驗(yàn)結(jié)果進(jìn)行了對比。對比計算時，考慮了再生混合混凝土組合抗壓強(qiáng)度的尺寸效應(yīng)。研究表明：單調(diào)加載時外置薄鋼板再生混合墻的水平力—水平位移計算曲線上升段與往復(fù)加載試驗(yàn)骨架曲線總體吻合較好，但計算曲線的下降段與試驗(yàn)骨架曲線差別明顯；在新、舊混凝土強(qiáng)度差小于10MPa時，廢棄混凝土取代率在10%～40%之間變化對外置薄鋼板再生混合墻的水平承載力和初始剛度影響較��；從用鋼量角度考慮，單純加厚墻端邊緣約束構(gòu)件（方鋼管）對提高外置薄鋼板再生混合墻的水平承載力可能更為有效；從方便廢棄混凝土塊體施工和提高該類構(gòu)件水平承載力兩方面考慮，建議實(shí)際工程中橫隔板間距與墻厚之比取為1.0～2.0。
[Abstract]:Recycled aggregate concrete is an effective way to use the waste concrete, but the production process of recycled aggregate is complicated and large energy consumption, and the preparation of recycled aggregate concrete still needs to consume a large amount of cement. Therefore, this paper proposes the direct use of large scale waste concrete thought in the structure, enhance the aggregate level from one to two a number of large scale to block or segment level to recycle the waste concrete. Ourprevious was on a large scale waste concrete blocks or segments of the mixed recycled concrete and its components are studied, on the basis of the further development of the size effect of concrete mixing and compression of thin external regeneration to investigate the regeneration performance of hybrid steel plate wall two.
The main work of this article includes:
Through the 51 mixed recycled concrete specimens and 36 cylinder test compression test pieces, reveals the specimen size, waste concrete block feature size and other factors on the compressive strength of recycled concrete mixing, influences of elastic modulus and peak strain. The study shows that the characteristic ratio remained unchanged in the case of recycled mixture concrete compressive strength decreases with the increase of specimen size, both with the size effect law also meet the size effect law amendment; the specimen size remains unchanged, with the combination of characteristics of compressive strength ratio increases; the combination of compressive strength and characteristics are in good agreement with the quantitative relationship between the with the test results; combined forecasting of compressive strength formula can be considered at the same time try to build change the size and shape of waste concrete block feature size and has good precision The influence of the size of the specimen and the size of the discarded concrete block on the modulus of elasticity and the peak strain of regenerated mixed concrete is limited.
Using digital image correlation (Digital Image Correlation, referred to as DIC) compression failure process measurement technology of recycled concrete mixture was revealed, research shows that waste between concrete blocks and new concrete interface does not appear obvious agglomeration phenomenon of crack germination and expansion, the late development of cracks in concrete and concrete block through new waste the way the body.
Regeneration of quasi static test on mixed wall through 7 pieces of external steel sheet, analyzes the waste concrete replacement rate, plate thickness, axial compression ratio, diaphragm spacing, height to width ratio on the seismic performance of the specimen. Based on the new, combined strength of old concrete, the approximate calculation and Analysis on bearing capacity test the water level, compares the bearing capacity and the total amount of steel under the condition of the same level and reinforced concrete wall. The study shows that the waste concrete replacement rate changes on the initial stiffness of the specimen in 0 ~ 33%, the horizontal bearing capacity, failure displacement angle, energy dissipation capacity and seismic performance lag curve shape effect; external thin steel plate regeneration mixed wall design of axial compression ratio should not exceed 0.35; the thickness of the wall thickness of the steel plate and the ratio of up to 120 of the cases, the external wall is thin steel recycled mixture has stable hysteretic energy and deformation The ability to damage displacement angle to meet the needs of current seismic code; external wall with thin steel plate mixed recycled or slightly higher energy dissipation capacity and reinforced concrete wall is basically the same; the amount of steel in the general case, the external thin steel plate and reinforced concrete wall with mixed recycled base the considerable level of capacity.
Using ABAQUS software, a finite element model is established for the external wall of the thin steel plate mixed recycled, the effects of main parameters on the component level of force displacement curve, and compared with the experiment results. Comparing the calculation, considering the size effect of concrete compressive strength of recycled mixture combination. The research results show: monotonic loading when the external force level of thin steel plate regeneration mixed wall curve calculation of horizontal displacement ascent and reciprocating loading test skeleton curve of overall good agreement, but decreased with the test curve skeleton curve the difference; in the new, old concrete strength is less than 10MPa when the waste concrete replacement rate in 10% ~ 40% between the changes of the external thin the level of plate regeneration mixed wall less influence bearing capacity and initial stiffness; considering the amount of steel angle, simple thickened wall end boundary elements (tube) to improve The horizontal bearing capacity of the outer thin steel plate regenerative mixing wall may be more effective. Considering the two aspects of convenient construction of the waste concrete block and improving the horizontal bearing capacity of such members, it is suggested that the ratio of diaphragm spacing to wall thickness is 1 to 2.0. in practical engineering.

【學(xué)位授予單位】：華南理工大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2013
【分類號】：TU528;TU352.11

【引證文獻(xiàn)】

相關(guān)期刊論文 前1條

1 張志軍;王曉芳;喬建軍;白茜;;混凝土受壓與受拉性能的尺寸效應(yīng)研究[J];商品混凝土;2014年07期

本文編號：1552989