本文關(guān)鍵詞：廢棄磚再生骨料在混凝土中的應(yīng)用研究　出處：《安徽建筑大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 碎磚骨料 再生混凝土 強(qiáng)度 耐久性 孔結(jié)構(gòu)

【摘要】：再生混凝土是新型綠色材料,有效解決了建筑垃圾回收利用問題。目前,混凝土的耐久性問題越來越受到關(guān)注,研究?jī)?nèi)容不斷深入,研究領(lǐng)域不斷延伸,而再生混凝土由于再生骨料的加入,耐久性問題研究變的更為復(fù)雜,耐久性機(jī)理分析也更加困難。本試驗(yàn)研究的是以碎磚作為再生粗骨料的再生混凝土耐久性能。試驗(yàn)中,碎磚骨料取代率為30%,Ⅰ級(jí)粉煤灰和減水劑摻量分別為10%和1.5%,采用C40混凝土的配合比。由于再生碎磚骨料吸水性強(qiáng),需要調(diào)整單位用水量,本試驗(yàn)中額外用水量為10%。試驗(yàn)中,先檢驗(yàn)再生混凝土28d抗壓、抗折強(qiáng)度,測(cè)試了再生混凝土的動(dòng)彈性模量,并與相同配合比的天然碎石混凝土進(jìn)行了對(duì)比。在了解碎磚骨料再生混凝土力學(xué)性能的基礎(chǔ)上,研究了碎磚骨料再生混凝土的耐久性能和內(nèi)部孔隙結(jié)構(gòu),試驗(yàn)結(jié)果如下:30%碎磚再生骨料替代天然碎石,再生混凝土的強(qiáng)度變化比較明顯,抗壓、抗折強(qiáng)度降低幅度分別為13.47%和4.38%,抗壓強(qiáng)度衰減速度比抗折強(qiáng)度快,動(dòng)彈性模量降低了,降低幅度達(dá)到11.18%。再生混凝土強(qiáng)度雖然有所降低,但是超出試驗(yàn)配制強(qiáng)度C40,平均值達(dá)到53.78MPa。與相同配比的天然碎石骨料混凝土相比,摻加30%碎磚骨料的再生混凝土的耐久性能略有差異。收縮性能方面,再生混凝土3d齡期的收縮應(yīng)變達(dá)到690×10-6,比普通混凝土高46.8%,收縮較大。同時(shí),發(fā)現(xiàn)摻加碎磚骨料的再生混凝土的平均滲水高度達(dá)到15mm,比普通混凝土高25%,而空氣滲透系數(shù)干態(tài)情況下達(dá)到0.058×10-12m2,濕態(tài)情況下達(dá)到0.032×10-12m2,均比普通混凝土高50%以上。摻加碎磚骨料的再生混凝土抗氯離子滲透性能也相對(duì)較差,DRCM達(dá)到9.37×10-12m2/s,比普通混凝土高86.1%。但是在抗硫酸鹽侵蝕性能方面,20次硫酸鹽干濕循環(huán)后,再生混凝土的質(zhì)量未出現(xiàn)衰減,且相對(duì)動(dòng)彈性模量保持在98%以上,即摻加碎磚骨料的再生混凝土抗硫酸侵蝕性能幾乎沒有影響。不僅如此,碎磚骨料再生混凝土抗碳化性能和抗凍性能均較好。其中,再生混凝土28d碳化深度為0mm,250次凍融循環(huán)后,再生混凝土的質(zhì)量損失率只有0.8%,相對(duì)動(dòng)彈性模量保持在71.1%以上,試件未破壞。研究了再生混凝土硬化后的氣孔結(jié)構(gòu),結(jié)果發(fā)現(xiàn):再生混凝土內(nèi)部的平均孔徑達(dá)到0.065mm,氣泡間距系數(shù)達(dá)到0.093mm,僅比普通混凝土的平均孔徑和氣泡間距系數(shù)分別高0.025mm以及0.005mm。由此可見,再生混凝土的氣泡間距系數(shù)也較小,所以抗凍性能較好。再生混凝土耐久性研究尚處在初級(jí)階段,有大量需要解決的問題。如何將實(shí)驗(yàn)室中的試驗(yàn)結(jié)果與實(shí)際環(huán)境中的耐久性損傷聯(lián)系起來,如何將再生混凝土的宏觀性能和微觀機(jī)理結(jié)合起來等問題還需要進(jìn)一步的研究。有關(guān)再生混凝土的耐久性標(biāo)準(zhǔn)還不完善,需要完善的標(biāo)準(zhǔn)來規(guī)范和指導(dǎo)來再生混凝土的耐久性設(shè)計(jì)和使用過程中的維護(hù)以及使用壽命的評(píng)估。
[Abstract]:Recycled concrete is a new kind of green material, which effectively solves the problem of recycling construction waste. At present, the durability of concrete has been paid more and more attention. However, due to the addition of recycled aggregate, the durability of recycled concrete becomes more complex. Durability mechanism analysis is also more difficult. In this experiment, the durability of recycled concrete with broken brick as recycled coarse aggregate is studied. In the test, the replacement ratio of broken brick aggregate is 30%. The mixing amount of grade I fly ash and water reducer is 10% and 1.5 respectively. The mixture ratio of C40 concrete is adopted. Because of the strong water absorption of recycled broken brick aggregate, it is necessary to adjust the unit water consumption. In this experiment, the additional water consumption is 10. In the test, the compressive and flexural strength of recycled concrete is first tested for 28 days, and the dynamic elastic modulus of recycled concrete is tested. On the basis of understanding the mechanical properties of recycled concrete of broken brick aggregate, the durability and internal pore structure of recycled concrete of broken brick aggregate are studied. The test results are as follows: the recycled aggregate of 30% broken brick replaces the natural crushed stone. The strength of recycled concrete changes obviously, the reduction of compressive strength and flexural strength are 13.47% and 4.38% respectively. The attenuation speed of compressive strength is faster than that of flexural strength, and the dynamic elastic modulus is reduced to 11.18%. Although the strength of recycled concrete has been reduced, the strength of recycled concrete is higher than that of experimental compounding strength C40. The average value is 53.78 MPA. Compared with the same proportion of natural crushed stone aggregate concrete, the durability of recycled concrete mixed with 30% crushed brick aggregate is slightly different. The shrinkage strain of recycled concrete is 690 脳 10 ~ (-6), which is 46.8% higher than that of ordinary concrete. It is found that the average seepage height of recycled concrete mixed with crushed brick aggregate is 15 mm, which is 25% higher than that of ordinary concrete, while the air permeability coefficient is 0.058 脳 10 ~ (-12) m ~ 2 in dry state. In wet condition, 0.032 脳 10 ~ (-12) m ~ (2), which is more than 50% higher than that of ordinary concrete, and the permeability of recycled concrete mixed with crushed brick aggregate is also relatively poor. The DRCM reached 9.37 脳 10 ~ (-12) m ~ (2 / s), 86.1 times higher than that of ordinary concrete. The mass of recycled concrete is not attenuated, and the relative dynamic modulus of elasticity is kept above 98%, that is, the sulfuric acid corrosion resistance of recycled concrete with crushed brick aggregate has little effect on it. The carbonation resistance and freezing resistance of recycled concrete of broken brick aggregate are good, among them, the carbonation depth of recycled concrete is 0 mm / 250 times after freezing and thawing cycle for 28 days. The mass loss rate of recycled concrete is only 0. 8 and the relative dynamic modulus of elasticity remains above 71.1%. The pore structure of recycled concrete after hardening is studied. The results show that the average aperture of recycled concrete is 0.065 mm and the coefficient of bubble spacing is 0.093 mm. The average pore diameter and bubble spacing coefficient of recycled concrete are only 0.025 mm and 0.005 mm higher than that of ordinary concrete. Therefore, the durability of recycled concrete is still in the primary stage, there are a lot of problems to be solved. How to link the test results in the laboratory with the durability damage in the actual environment. How to combine the macro performance and micro mechanism of recycled concrete needs further research. The durability standard of recycled concrete is not perfect. Perfect standards are needed to standardize and guide the durability design and maintenance of recycled concrete and to evaluate its service life.
【學(xué)位授予單位】：安徽建筑大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TU528

【參考文獻(xiàn)】

相關(guān)期刊論文 前2條

1 張李黎;柳炳康;胡波;;再生混凝土抗?jié)B性試驗(yàn)研究[J];合肥工業(yè)大學(xué)學(xué)報(bào)(自然科學(xué)版);2009年04期

2 王中平;王振;;混凝土導(dǎo)電量與氣體滲透系數(shù)的相關(guān)性[J];建筑材料學(xué)報(bào);2010年01期

相關(guān)碩士學(xué)位論文 前1條

1 孟慶超;混凝土耐久性與孔結(jié)構(gòu)影響因素的研究[D];哈爾濱工業(yè)大學(xué);2006年

，

本文編號(hào)：1372437