本文選題：巖石基礦物摻合料 + 孔結(jié)構(gòu)�。� 參考：《中南大學(xué)》2014年碩士論文

【摘要】：摘要：在機(jī)制砂和碎石等集料的生產(chǎn)過程中產(chǎn)生的巖石基礦物摻合料按化學(xué)成分的不同可分為鈣質(zhì)和硅質(zhì)兩大類,開展巖石基礦物摻合料對水泥基膠凝材料性能的影響研究,對其加以利用,不僅能減少水泥用量,改善水泥基膠凝材料性能,還能降低環(huán)境污染,具有很好的技術(shù)經(jīng)濟(jì)效益。同時(shí),為巖石基礦物摻合料在工程中的廣泛應(yīng)用奠定理論基礎(chǔ)。 本文依托國家自然科學(xué)基金項(xiàng)目“新型巖石基礦物摻合料體系的理論基礎(chǔ)與工程應(yīng)用研究(項(xiàng)目編號51278497)”,主要針對水泥-巖石基礦物摻合料膠凝體系物理力學(xué)性能和耐久性等問題進(jìn)行了研究。分析了鈣質(zhì)巖石基礦物摻合料和硅質(zhì)巖石基礦物摻合料分別對水泥凝結(jié)時(shí)間、膠砂流動(dòng)性、強(qiáng)度性能和抗硫酸鹽侵蝕性能的影響規(guī)律。主要研究內(nèi)容和成果如下： 1.研究了巖石基礦物摻合料對水泥凝結(jié)時(shí)間和流動(dòng)性的影響 (1)石灰石粉和大理石粉顯著縮短了水泥凈漿的初凝和終凝時(shí)間,且隨其摻量的增加,水泥的凝結(jié)時(shí)間呈逐漸減小的趨勢；水凝膠砂的流動(dòng)度隨石灰石粉和大理石粉的摻加而得以改善,且石粉摻量越多,水凝膠砂流動(dòng)度越大。隨白云石粉摻量的增加,水泥凈漿的初凝和終凝時(shí)間均較基準(zhǔn)組有所延長；白云石粉摻量較低時(shí),水泥膠砂的流動(dòng)度較基準(zhǔn)組顯著提高,但隨其摻量的增加,水泥膠砂的流動(dòng)度逐漸降低。 (2)花崗巖石粉和石英石粉的摻入對水泥凈漿的初凝、終凝的影響規(guī)律一致,即水泥凈漿的初凝、終凝時(shí)間均較基準(zhǔn)組顯著縮短；隨花崗巖石粉摻量的增加,水泥凝結(jié)時(shí)間呈逐漸增大的趨勢。玄武巖石粉的摻加使得水泥的初凝、終凝時(shí)間均較基準(zhǔn)組縮短,且隨玄武巖石粉摻量的增加,凝結(jié)時(shí)間逐漸減小�；◢弾r、玄武巖和石英石粉對水泥膠砂流動(dòng)度的影響一致,當(dāng)其摻量較小時(shí),能有效提高水泥膠砂的流動(dòng)度,但隨其摻量的增加,水泥膠砂流動(dòng)度逐漸降低。 2.研究了巖石基礦物摻合料對水泥膠砂強(qiáng)度的影響 (1)石灰石粉、白云石粉和大理石粉三種鈣質(zhì)巖石基礦物摻合料能提高水泥膠砂早齡期強(qiáng)度,且試件的抗折強(qiáng)度隨摻合料摻量的增加呈先增大后降低的趨勢,當(dāng)摻量為5%時(shí),水泥膠砂強(qiáng)度達(dá)最大；但水泥膠砂后期強(qiáng)度則隨摻合料摻量的增加而逐漸降低,且均低于基準(zhǔn)組。當(dāng)鈣質(zhì)巖石基礦物摻合料摻量一定時(shí),隨其細(xì)度的增大,水泥膠砂強(qiáng)度大致呈先增大后降低的趨勢。 (2)花崗巖石粉、玄武巖石粉及石英石粉三種硅質(zhì)巖石基礦物摻合料的摻入使得水泥膠砂各齡期強(qiáng)度均低于基準(zhǔn)組,且摻量越大,強(qiáng)度降低越顯著�；◢弾r石粉和石英石粉等量取代水泥時(shí),水泥膠砂試件抗折強(qiáng)度隨其摻量的增加而逐漸降低,早齡期抗壓強(qiáng)度隨摻量的增加呈先增大后降低的趨勢；摻玄武巖石粉的水泥膠砂試件抗折、抗壓強(qiáng)度均隨其摻量的增加呈先增大后降低的趨勢,當(dāng)玄武巖石粉摻量為10%時(shí),水泥膠砂強(qiáng)度達(dá)最大。 3.研究了巖石基礦物摻合料對水泥膠砂孔結(jié)構(gòu)的影響 適量摻量的鈣質(zhì)巖石基礦物摻合料能降低水泥膠砂早齡期的質(zhì)量吸水率和平均孔徑,水泥膠砂14d至56d齡期的質(zhì)量吸水率和平均孔徑均高于基準(zhǔn)組,且隨鈣質(zhì)巖石基礦物摻合料摻量的增加而逐漸增大。硅質(zhì)巖石基礦物摻合料的摻入增大了水泥膠砂各齡期的孔隙率,且摻量越多,孔隙率越大。 4.研究了巖石基礦物摻合料對混凝土抗氯離子滲透性能的影響 鈣質(zhì)和硅質(zhì)巖石基礦物摻合料的摻入均對混凝土28d齡期時(shí)的抗氯離子滲透性能產(chǎn)生不利影響,混凝土的電通量隨摻合料摻量的增加呈逐漸增大的趨勢,且均高于基準(zhǔn)組。 5.研究了摻石灰石粉水泥凈漿在低溫硫酸鹽侵蝕下的破壞及其作用機(jī)理 摻石灰石粉的水泥凈漿試件浸泡于低溫(5℃)環(huán)境下不同濃度的Na2SO4溶液以及5%MgSO4溶液中時(shí),均發(fā)生了碳硫硅鈣石型硫酸鹽侵蝕,且隨著腐蝕時(shí)間的延長和硫酸鈉濃度的增加,凈漿表面的腐蝕破壞加劇。這是由于溶液中的S042-通過孔隙滲透至水泥石內(nèi)部,直接與水泥石中的Ca(OH)2或C-S-H凝膠反應(yīng)生成CaSO4·2H2O,在低溫環(huán)境下,C-S-H凝膠與CaSO4·2H2O、石灰石粉和水直接反應(yīng)生成碳硫硅鈣石。當(dāng)溶液濃度均為5%時(shí),浸泡于MgSO4溶液中的凈漿試件比Na2SO4溶液中的試件腐蝕更為嚴(yán)重。這是因?yàn)樵撨^程不僅發(fā)生了外部的SO42-9滲透至水泥石內(nèi)部生成碳硫硅鈣石的反應(yīng),還生成了Mg(OH)2,導(dǎo)致了C-S-H凝膠的分解,進(jìn)一步促進(jìn)了碳硫硅鈣石的生成反應(yīng)。
[Abstract]:Abstract : The rock - based mineral admixture produced in the course of producing aggregate such as mechanism sand and crushed stone can be divided into two categories of calcium and siliceous rock according to the chemical composition , and the influence of rock - based mineral admixture on the properties of cement - based cementing material is studied . It can not only reduce the cement consumption , improve the properties of cement - based cementing material , but also reduce environmental pollution , and has good technical and economic benefits .

Based on the theoretical basis and engineering application of the new rock - based mineral admixture system of the National Natural Science Foundation Project ( Project No . 51278497 ) , this paper mainly studies the physical and mechanical properties and durability of cement - rock - based mineral admixture cementing system .

1 . The influence of rock - based mineral admixture on the setting time and fluidity of cement is studied .

( 1 ) the lime stone powder and the marble powder remarkably shorten the initial setting and the final setting time of the cement paste , and the setting time of the cement gradually decreases with the increase of the mixing amount thereof ;
The fluidity of the hydrogel is improved with the addition of limestone powder and marble powder , and the more the content of stone powder is , the greater the flow degree of the hydrogel sand . With the increase of the amount of dolomite powder , the initial setting and the final setting time of the cement paste are prolonged compared with the reference group ;
When the amount of dolomite powder is low , the fluidity of cement sand is obviously improved compared with the reference group , but the fluidity of cement sand is gradually decreased with the increase of mixing amount .

( 2 ) The effect of the mixing of granite stone powder and quartz stone powder on the initial setting and final setting of cement paste is consistent , that is , the initial setting and the final setting time of cement paste are obviously shortened compared with the reference group ;
With the increase of the content of the granite stone powder , the setting time of cement is gradually increased . The addition of basalt stone powder makes the initial setting and final setting time of the cement be shorter than that of the reference group , and the setting time is gradually decreased with the increase of the content of the basalt stone powder . The granite , basalt and quartz stone powder have the same effect on the fluidity of the cement mortar , but the fluidity of the cement mortar can be effectively improved when the amount of the granite , basalt and quartz stone powder is increased . However , the fluidity of the cement mortar decreases with the increase of the mixing amount .

2 . The influence of rock - based mineral admixture on the strength of cement mortar is studied .

( 1 ) The lime stone powder , dolomite powder and marble powder three calcareous rock - based mineral admixture can improve the early age strength of the cement mortar , and the flexural strength of the test piece decreases with the increase of the blending amount of the admixture , and the strength of the cement mortar reaches the maximum when the mixing amount is 5 % ;
however , that late strength of cement mortar gradually decrease with the increase of the amount of admixture , and is lower than that of the reference group .

( 2 ) The incorporation of three kinds of siliceous rock - based mineral admixtures of granite stone powder , basalt stone powder and quartz stone powder makes the strength of each age of the cement paste lower than that of the reference group , and the higher the mixing amount , the more significant the strength decreases . When the equivalent amount of the granite stone powder and quartz stone powder replaces the cement , the flexural strength of the cement colloidal sand test piece decreases gradually with the increase of the content of the mixture , and the compressive strength of the early - age compressive strength decreases with the increase of the mixing amount ;
The flexural and compressive strength of the cement - cement sand samples with basalt rock powder increase with the increase of their content , and the strength of cement mortar is the biggest when the content of basalt stone powder is 10 % .

3 . The influence of rock - based mineral admixture on the pore structure of cement mortar is studied .

The quality water absorption and average pore size of cement - cement - sand early - age are reduced by appropriate amount of calcium - rock - based mineral admixture , and the quality water absorption and average pore diameter of cement - cement sand from 14d to 56d are higher than that of the reference group , and gradually increase with the increase of the mixing amount of the calcium - rock - based mineral admixture . The incorporation of the siliceous rock - based mineral admixture increases the porosity of each age of the cement - cement sand , and the higher the mixing amount , the greater the porosity .

4 . The influence of rock - based mineral admixture on chloride ion permeability of concrete is studied .

Both the calcium and the siliceous rock - based mineral admixture have an adverse effect on the anti - chloride ion permeability during the 28d age of the concrete , and the electric flux of the concrete gradually increases with the addition of the admixture , and is higher than the reference group .

5 . The damage and mechanism of cement paste with limestone powder under low temperature sulfate attack are studied .

When the concentration of the solution is 5 % , the C - S - H gel is directly reacted with Ca ( OH ) 2 or C - S - H gel in cement stone to form CaSO4.2H2 . When the concentration of the solution is 5 % , the C - S - H gel is directly reacted with Ca ( OH ) 2 or C - S - H gel in cement stone to form CaSO4 路 2H 2O .

【學(xué)位授予單位】：中南大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：TU528.01

【參考文獻(xiàn)】

相關(guān)博士學(xué)位論文 前1條

1 王稷良;機(jī)制砂特性對混凝土性能的影響及機(jī)理研究[D];武漢理工大學(xué);2008年

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本文編號：1762792