本文選題：水泥凈漿 + 砂漿��； 參考：《哈爾濱工業(yè)大學(xué)》2015年碩士論文

【摘要】：拌合物流變性能直接決定了混凝土的施工難易程度和施工質(zhì)量,因而流變性能是現(xiàn)代混凝土配合比設(shè)計(jì)中最重要的技術(shù)指標(biāo)之一。目前,國(guó)內(nèi)外絕大多數(shù)研究和現(xiàn)行混凝土配合比設(shè)計(jì)規(guī)程中對(duì)于流變性能的設(shè)計(jì)和調(diào)整主要是基于經(jīng)驗(yàn)公式,沒(méi)有考慮到實(shí)際原材料顆粒特性不同而產(chǎn)生的重要影響,從而導(dǎo)致不同研究者的研究結(jié)果不一致和實(shí)際工程混凝土的配合比設(shè)計(jì)經(jīng)濟(jì)性差。因此,本課題基于顆粒堆積與懸浮液理論,從水泥凈漿、水泥砂漿、混凝土拌合物三個(gè)層次分別研究膠凝材料、細(xì)骨料、粗骨料顆粒組成特性不同對(duì)拌合物流變性能的影響規(guī)律,通過(guò)確定顆粒特性與流變性能之間的對(duì)應(yīng)關(guān)系,為實(shí)際混凝土配合比優(yōu)化設(shè)計(jì)奠定理論基礎(chǔ)。在水泥凈漿體系中,通過(guò)不同摻量、不同細(xì)度的粉煤灰、礦渣粉代替水泥以改變膠凝材料體系的顆粒組成與特性,結(jié)果發(fā)現(xiàn):在一定范圍內(nèi),增加粉煤灰的摻量會(huì)降低水泥凈漿粘度,提高水泥凈漿流動(dòng)度。當(dāng)摻入過(guò)細(xì)粉煤灰時(shí),對(duì)水泥漿體的流動(dòng)性不利。隨著礦渣摻量的不斷增加,水泥凈漿的流動(dòng)度變大,粘度變小。復(fù)合膠凝材料顆粒與Fuller曲線之間相差的面積S1和S2與水泥凈漿流變性能有較好的相關(guān)關(guān)系。S1越大,水泥凈漿流動(dòng)度越小,粘度越大;S2越大,水泥凈漿流動(dòng)度越大,粘度越小。當(dāng)在較小范圍內(nèi)變化砂的細(xì)度模數(shù)時(shí),水泥砂漿的流動(dòng)性不是隨著砂的細(xì)度模數(shù)的變大而變大。這就表明即使砂子的細(xì)度模數(shù)相同,如果各個(gè)粒級(jí)細(xì)顆粒的含量不同,水泥砂漿的流動(dòng)性也會(huì)存在顯著差異。所以在研究細(xì)集料砂子對(duì)水泥砂漿流變性能的影響時(shí),不能只以砂的細(xì)度模數(shù)作為參考,還應(yīng)該考慮砂的顆粒級(jí)配。水泥砂漿的屈服剪切應(yīng)力和塑性粘度均隨漿體富余系數(shù)增加而降低,流動(dòng)度則隨漿體富余系數(shù)增加而增大;增大漿體富余系數(shù)到一定值,其變化較平緩。骨料堆積空隙率和骨料總比表面積隨著針片狀含量增加而增大,從而導(dǎo)致相同配合比時(shí)混凝土的流動(dòng)性變差;設(shè)計(jì)混凝土配合比應(yīng)該控制針片狀粗骨料含量在10%以內(nèi),挑選顆粒形態(tài)好的粗骨料顆粒,能顯著改善混凝土拌合物流變性能。相同條件下,混凝土的坍落度和擴(kuò)展度均隨砂漿富余系數(shù)增加而增大,但在達(dá)到2.5~3.5以后,繼續(xù)增加砂漿量對(duì)坍落度和擴(kuò)展度的增加效果不明顯。
[Abstract]:The rheological properties of the mixture directly determine the construction difficulty and the construction quality of concrete, so the rheological properties are one of the most important technical indexes in the design of modern concrete mix ratio. At present, the design and adjustment of the rheological properties in most of the research and current concrete mix design regulations at home and abroad is mainly based on the design and adjustment of the rheological properties. The experimental formula does not take into account the important effect of the different properties of the actual raw material, which leads to the difference of the research results of different researchers and the poor design economy of the actual engineering concrete. Therefore, this subject is based on the theory of particle accumulation and suspension, from three layers of cement paste, cement mortar and concrete mix. The effects of different properties of cementitious materials, fine aggregate and coarse aggregate particles on the rheological properties of the mixture are studied, and the theoretical basis for the optimization of concrete mix ratio is established by determining the corresponding relationship between the particle properties and rheological properties. In the cement slurry system, the fly ash with different quantities and different fineness is passed in the cement slurry system. Slag powder instead of cement is used to change the particle composition and characteristics of the cementitious material system. It is found that increasing the amount of fly ash in a certain range will reduce the viscosity of cement paste and increase the fluidity of cement paste. When adding fine fly ash, the fluidity of cement slurry is not good. With the increase of slag content, the flow of cement paste is increased. The area S1 and S2 difference between the particle size and the Fuller curve of the composite cementitious material has a better correlation with the rheological properties of cement paste, the greater the.S1, the smaller the flow degree of cement paste, the greater the viscosity; the larger the S2, the greater the cement paste fluidity and the smaller the viscosity. When the fineness modulus of the sand is changed in a small range, the water can be changed in a smaller range. The fluidity of the mortar is not larger than the size of the sand. This shows that if the fine modulus of the sand is the same, there is a significant difference in the fluidity of the cement mortar if the content of the fine particles is different. So, it is not only fine to study the effect of the fine aggregate sand on the rheological properties of the cement mortar. As a reference, the grain gradation of sand should be considered as a reference. The yield shear stress and plastic viscosity of the cement mortar are decreased with the increase of the slurry surplus coefficient, and the flow degree increases with the increase of the slurry surplus coefficient; the change of the slurry surplus coefficient to a certain value is slow. The porosity of aggregate accumulation and the aggregate surface area of aggregate The fluidity of the concrete increases with the increase of the needle sheet content, which leads to the poor fluidity of concrete in the same mix ratio. The design concrete mix ratio should control the content of the coarse aggregate of the needle like coarse aggregate within 10%, and select the coarse aggregate particles with good particle shape. The concrete slump and expansion can be improved significantly. The degree increases with the increase of mortar surplus coefficient, but after reaching 2.5~3.5, the effect of increasing mortar volume on slump and expansion is not obvious.

【學(xué)位授予單位】：哈爾濱工業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TU528

【引證文獻(xiàn)】

相關(guān)會(huì)議論文 前2條

1 亢景付;;高性能混凝土拌和物流變性能測(cè)試方法探討[A];HPC2002第四屆全國(guó)高性能混凝土學(xué)術(shù)研討會(huì)論文集[C];2002年

2 陳國(guó)強(qiáng);;基于最大密實(shí)度曲線理論的微表處集料級(jí)配范圍設(shè)計(jì)方法研究[A];2014年10月建筑科技與管理學(xué)術(shù)交流會(huì)論文集[C];2014年

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本文編號(hào)：1776159