預制混凝土構(gòu)件二次振搗及蒸汽養(yǎng)護技術(shù)研究
發(fā)布時間：2019-04-11 19:17
【摘要】：現(xiàn)階段對裝配式混凝土結(jié)構(gòu)的研究正處于升溫階段,由于要求實現(xiàn)建筑產(chǎn)業(yè)化邁入標準化新階段,因此對于預制混凝土構(gòu)件的強度以及其生產(chǎn)時間也愈加重視,而這些都與混凝土構(gòu)件的養(yǎng)護息息相關(guān)。但是在預制構(gòu)件廠生產(chǎn)流水線的運行過程中,養(yǎng)護占用了大量的時間,而且由于技術(shù)的不成熟,時間也存在很大的不可控性。就目前預制構(gòu)件廠的建立形勢來看,大部分預制構(gòu)件廠均采用蒸汽養(yǎng)護的方式對混凝土構(gòu)件進行養(yǎng)護,二次蒸汽養(yǎng)護又是較為先進的蒸汽養(yǎng)護方法。因此,對二次蒸汽養(yǎng)護的優(yōu)化設(shè)計以及對二次蒸汽養(yǎng)護窯節(jié)能設(shè)計的研究就很必要了。本文基于國內(nèi)外對于蒸汽養(yǎng)護優(yōu)化的研究現(xiàn)狀,通過參考具體的案例,對現(xiàn)有的一些蒸汽養(yǎng)護的優(yōu)化措施進行了比較研究,并且提出了控制水膠比進行二次振搗以提高混凝土早期強度的措施,其目的在于使得混凝土構(gòu)件更穩(wěn)定的適應高溫高壓蒸汽養(yǎng)護,也能一定幅度減少蒸汽養(yǎng)護的時間,提高效率;同時通過摻入礦粉、粉煤灰以及控制砂率的措施對二次蒸汽養(yǎng)護的優(yōu)化進行了研究,目的應用改變混凝土材料組分的方式來提高生產(chǎn)效率,并且提高預制混凝土構(gòu)件后期強度;最后提出幾種降低養(yǎng)護窯生產(chǎn)成本,節(jié)能減排的假設(shè),并探討其可能性。科學合理的安排養(yǎng)護流程,既要能夠達到產(chǎn)品所要求的使用功能,又要盡量簡化操作流程,提高生產(chǎn)的效率,節(jié)約生產(chǎn)的成本。通過研究可得出以下結(jié)論:(1)通過對現(xiàn)場施工中運用二次振搗案例的分析以及對混凝土構(gòu)件初凝時間的計算,在恰當時間下的二次振搗可以提高二次蒸汽養(yǎng)護的效率,并且使混凝土后期強度增長更加均勻化。同時通過試驗證明了在預制構(gòu)件廠生產(chǎn)線中加入二次振搗后,混凝土后期強度有明顯增加,特別是低標號的混凝土:C30混凝土構(gòu)件經(jīng)過二次振搗后可以提高后期強度20%～25%,而C50混凝土構(gòu)件經(jīng)過二次振搗后僅僅可以提高后期強度10%～15%;而且在二次蒸汽養(yǎng)護的條件下,二次振搗可以在不影響28d強度的前提下節(jié)省10%的水泥用量。同時發(fā)現(xiàn)附著式振搗與插入式振搗交替應用效果不如插入式振搗。(2)合理控制常溫初級養(yǎng)護的時間,使得混凝土的強度在高溫高壓階段可以更好的增長。通過實際案例分析,以及最低成熟度值的計算,常溫初級養(yǎng)護的時間在2～4h時,可以有效的改善混凝土內(nèi)部孔隙結(jié)構(gòu),并且能夠合理的控制流水節(jié)拍。(3)通過對案例的分析,對二次蒸汽養(yǎng)護中高溫高壓階段的幾種影響因素進行了進一步的探究,包括升溫速率、恒溫時間以及恒溫溫度。升溫速率控制在15℃/h～20℃/h,這樣既可以防止升溫過程中水汽移動而導致的混凝土內(nèi)部孔隙率加大甚至開裂,也可以提高蒸汽養(yǎng)護的效率;如果選擇過低的恒溫溫度,則在這個獲得強度以及各項性能趨于穩(wěn)定的階段混凝土不能得到良好的強度以及性能發(fā)展;如果恒溫時間過長,在未完全水化的顆粒外則會形成隔離膜,延誤甚至阻礙混凝土后期強度的增長,因此恒溫溫度則選擇在50℃～60℃為宜,而恒溫時間則在3～4h為宜。(4)在礦粉-粉煤灰雙摻的案例中,通過對試驗數(shù)據(jù)的對比以及對雙摻比例的研究,雙摻量在40%時后期強度最大,脫模強度也可達到50MPa以上;而如果礦粉和粉煤灰的比例為5:3時,則混凝土 28d強度較高,但是90d強度較低,反之相反,這說明礦粉的主要作用在于提高混凝土的前期強度,而粉煤灰則對于混凝土后期強度的發(fā)展更加有利。(5)二次蒸汽養(yǎng)護中,提出了循環(huán)節(jié)能式立式養(yǎng)護窯的設(shè)計理念,即在常溫初級養(yǎng)護階段,在“n”式蒸養(yǎng)釜的排氣口處加一個管道,將余氣引入進氣口;在高溫高壓立式養(yǎng)護窯中,增設(shè)供氣閥門,在多臺蒸養(yǎng)釜連續(xù)運作期間,通過對余氣的反復利用實現(xiàn)循環(huán)節(jié)能。并且改善蒸汽噴射系統(tǒng),使蒸汽噴嘴組合更加合理化、均勻化。對蒸汽蓄熱器進行了研究,并且通過計算對拉法爾噴嘴的設(shè)計進行了優(yōu)化。通過對實際案例的分析,根據(jù)在遼寧宇輝新型建筑材料有限公司實習所學的知識,整合了以上幾點優(yōu)化二次蒸汽養(yǎng)護的因素,并且提出了預制構(gòu)件二次振搗的方案,理論聯(lián)系實際,最終撰寫本文。
[Abstract]:At present, the research of the assembled concrete structure is at the temperature rise stage, because it is required to realize the construction industrialization into the new stage of standardization, the strength of the prefabricated concrete component and the production time of the prefabricated concrete component are also more and more important, and these are closely related to the curing of the concrete component. But during the operation of the production line of the prefabricated part factory, the curing takes a great amount of time, and due to the immature technology of the technology, the time also has great incontrollability. In view of the current construction situation of the prefabricated part factory, most of the prefabricated parts are cured by steam curing, and the secondary steam curing is a more advanced method of steam curing. Therefore, it is necessary to study the optimum design of the secondary steam curing and the energy-saving design of the secondary steam curing kiln. Based on the research situation of the optimization of steam curing at home and abroad, this paper makes a comparative study on some of the existing optimization measures for steam curing by referring to the specific case, and puts forward the measures to control the secondary vibration of the water-to-glue ratio to improve the early strength of the concrete. The method has the advantages that the concrete member is more stable to the high-temperature and high-pressure steam curing, the time of the steam curing can be reduced at a certain amplitude, the efficiency is improved, and the optimization of the secondary steam curing is carried out through the measures of incorporating the mineral powder, the fly ash and the control sand ratio, The purpose of this paper is to improve the production efficiency by changing the components of concrete materials, and to improve the later strength of the precast concrete members. Finally, some assumptions to reduce the production cost, energy saving and emission reduction of the curing kiln are put forward, and the possibility is also discussed. And a scientific and reasonable arrangement and maintenance flow can be arranged, so that the use function required by the product can be achieved, the operation flow can be simplified as much as possible, the production efficiency is improved, and the production cost is saved. Through the study, the following conclusions can be drawn: (1) The efficiency of the secondary steam curing can be improved by the analysis of the case of secondary vibration and the calculation of the initial setting time of the concrete member in the field construction. And the later strength of the concrete is increased more uniformly. At the same time, it is proved that after the secondary vibration is added to the production line of the prefabricated part factory, the later strength of the concrete is obviously increased, especially the low-grade concrete: the C30 concrete component can improve the later strength by 20-25% after the secondary vibration, And the C50 concrete component can only improve the later strength by 10 to 15 percent after the secondary vibration, and the secondary vibration can save the cement consumption of 10 percent without affecting the strength of the 28d under the condition that the secondary steam is cured. At the same time, it is found that the alternative application effect of the attached vibration and the plug-in vibration is not as good as the plug-in And (2) reasonably controlling the time of primary curing at normal temperature, so that the strength of the concrete can be better increased in the high-temperature and high-pressure stage. Through the practical case analysis and the calculation of the minimum maturity value, the primary curing time of the room temperature is 2 to 4 hours, the internal pore structure of the concrete can be effectively improved, and the running water beat can be reasonably controlled. (3) Through the analysis of the case, the influence factors of the high-temperature and high-pressure stage in the secondary steam curing are further explored, including the temperature-raising rate, the constant-temperature time and the constant-temperature temperature. the temperature rise rate is controlled at the temperature of 15 DEG C/ h to 20 DEG C/ h, so that the internal porosity of the concrete can be increased or even cracked due to the water vapor movement during the temperature rise process, and the efficiency of the steam curing can be improved; if the low temperature of the constant temperature is selected, the strength and the performance of the concrete can not be obtained at the stage where the obtained strength and various performances are stable; if the constant temperature time is too long, an isolation film is formed outside the completely hydrated particles, and the delay even prevents the increase of the later strength of the concrete, Therefore, the temperature of the constant temperature is selected to be between 50 and 60 DEG C, and the constant temperature time is preferably 3 to 4 hours. and (4) in the case of the double-mixing of the mineral powder and the fly ash, the strength at the later stage and the release strength of the concrete 28d are higher when the proportion of the mineral powder and the fly ash is 5:3, by the comparison of the test data and the research on the double-doping proportion, the strength of the two-mixing is the maximum at the later stage of 40 percent, and the demoulding strength can reach more than 50 MPa; and if the proportion of the mineral powder and the fly ash is 5:3, the strength of the concrete 28d is high, However, that strength of the 90d is low, and vice versa, this indicates that the primary function of the mineral powder is to improve the early strength of the concrete, and the fly ash is more favorable for the development of the later strength of the concrete. (5) in the secondary steam curing, a design concept of a circular energy-saving type vertical maintenance kiln is put forward, namely, a pipeline is added at the exhaust port of the "n"-type steam-curing kettle in the normal-temperature primary curing stage, and the residual gas is introduced into the air inlet; in the high-temperature and high-pressure vertical maintenance kiln, an air supply valve is additionally arranged, During the continuous operation of a plurality of steam-curing kettles, the recycling energy-saving is realized through the repeated utilization of the residual gas. And the steam injection system is improved so that the steam nozzle combination is more reasonable and uniform. The steam heat accumulator was studied and the design of the Laval nozzle was optimized. Through the analysis of practical cases, based on the knowledge obtained in the practice of the new building material limited company in Yonghui, Liaoning, the factors of optimizing the secondary steam curing are completed, and the scheme of secondary vibration of the prefabricated parts is put forward, the theory is in practice, and the paper is finally written.
【學位授予單位】：沈陽建筑大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TU755.7
本文編號：2456679
[Abstract]:At present, the research of the assembled concrete structure is at the temperature rise stage, because it is required to realize the construction industrialization into the new stage of standardization, the strength of the prefabricated concrete component and the production time of the prefabricated concrete component are also more and more important, and these are closely related to the curing of the concrete component. But during the operation of the production line of the prefabricated part factory, the curing takes a great amount of time, and due to the immature technology of the technology, the time also has great incontrollability. In view of the current construction situation of the prefabricated part factory, most of the prefabricated parts are cured by steam curing, and the secondary steam curing is a more advanced method of steam curing. Therefore, it is necessary to study the optimum design of the secondary steam curing and the energy-saving design of the secondary steam curing kiln. Based on the research situation of the optimization of steam curing at home and abroad, this paper makes a comparative study on some of the existing optimization measures for steam curing by referring to the specific case, and puts forward the measures to control the secondary vibration of the water-to-glue ratio to improve the early strength of the concrete. The method has the advantages that the concrete member is more stable to the high-temperature and high-pressure steam curing, the time of the steam curing can be reduced at a certain amplitude, the efficiency is improved, and the optimization of the secondary steam curing is carried out through the measures of incorporating the mineral powder, the fly ash and the control sand ratio, The purpose of this paper is to improve the production efficiency by changing the components of concrete materials, and to improve the later strength of the precast concrete members. Finally, some assumptions to reduce the production cost, energy saving and emission reduction of the curing kiln are put forward, and the possibility is also discussed. And a scientific and reasonable arrangement and maintenance flow can be arranged, so that the use function required by the product can be achieved, the operation flow can be simplified as much as possible, the production efficiency is improved, and the production cost is saved. Through the study, the following conclusions can be drawn: (1) The efficiency of the secondary steam curing can be improved by the analysis of the case of secondary vibration and the calculation of the initial setting time of the concrete member in the field construction. And the later strength of the concrete is increased more uniformly. At the same time, it is proved that after the secondary vibration is added to the production line of the prefabricated part factory, the later strength of the concrete is obviously increased, especially the low-grade concrete: the C30 concrete component can improve the later strength by 20-25% after the secondary vibration, And the C50 concrete component can only improve the later strength by 10 to 15 percent after the secondary vibration, and the secondary vibration can save the cement consumption of 10 percent without affecting the strength of the 28d under the condition that the secondary steam is cured. At the same time, it is found that the alternative application effect of the attached vibration and the plug-in vibration is not as good as the plug-in And (2) reasonably controlling the time of primary curing at normal temperature, so that the strength of the concrete can be better increased in the high-temperature and high-pressure stage. Through the practical case analysis and the calculation of the minimum maturity value, the primary curing time of the room temperature is 2 to 4 hours, the internal pore structure of the concrete can be effectively improved, and the running water beat can be reasonably controlled. (3) Through the analysis of the case, the influence factors of the high-temperature and high-pressure stage in the secondary steam curing are further explored, including the temperature-raising rate, the constant-temperature time and the constant-temperature temperature. the temperature rise rate is controlled at the temperature of 15 DEG C/ h to 20 DEG C/ h, so that the internal porosity of the concrete can be increased or even cracked due to the water vapor movement during the temperature rise process, and the efficiency of the steam curing can be improved; if the low temperature of the constant temperature is selected, the strength and the performance of the concrete can not be obtained at the stage where the obtained strength and various performances are stable; if the constant temperature time is too long, an isolation film is formed outside the completely hydrated particles, and the delay even prevents the increase of the later strength of the concrete, Therefore, the temperature of the constant temperature is selected to be between 50 and 60 DEG C, and the constant temperature time is preferably 3 to 4 hours. and (4) in the case of the double-mixing of the mineral powder and the fly ash, the strength at the later stage and the release strength of the concrete 28d are higher when the proportion of the mineral powder and the fly ash is 5:3, by the comparison of the test data and the research on the double-doping proportion, the strength of the two-mixing is the maximum at the later stage of 40 percent, and the demoulding strength can reach more than 50 MPa; and if the proportion of the mineral powder and the fly ash is 5:3, the strength of the concrete 28d is high, However, that strength of the 90d is low, and vice versa, this indicates that the primary function of the mineral powder is to improve the early strength of the concrete, and the fly ash is more favorable for the development of the later strength of the concrete. (5) in the secondary steam curing, a design concept of a circular energy-saving type vertical maintenance kiln is put forward, namely, a pipeline is added at the exhaust port of the "n"-type steam-curing kettle in the normal-temperature primary curing stage, and the residual gas is introduced into the air inlet; in the high-temperature and high-pressure vertical maintenance kiln, an air supply valve is additionally arranged, During the continuous operation of a plurality of steam-curing kettles, the recycling energy-saving is realized through the repeated utilization of the residual gas. And the steam injection system is improved so that the steam nozzle combination is more reasonable and uniform. The steam heat accumulator was studied and the design of the Laval nozzle was optimized. Through the analysis of practical cases, based on the knowledge obtained in the practice of the new building material limited company in Yonghui, Liaoning, the factors of optimizing the secondary steam curing are completed, and the scheme of secondary vibration of the prefabricated parts is put forward, the theory is in practice, and the paper is finally written.
【學位授予單位】：沈陽建筑大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TU755.7
【參考文獻】
相關(guān)期刊論文 前10條
1 肖茜;伍勇華;南峰;何廷樹;李論;;不同種類外加劑對混凝土蒸養(yǎng)強度的影響[J];混凝土與水泥制品;2012年12期
2 陳子康;周云;張季超;吳從曉;;裝配式混凝土框架結(jié)構(gòu)的研究與應用[J];工程抗震與加固改造;2012年04期
3 黃小坤;田春雨;;預制裝配式混凝土結(jié)構(gòu)研究[J];住宅產(chǎn)業(yè);2010年09期
4 馬保國;王明遠;溫小棟;鄢佳佳;許錦華;陳龍;;不同蒸養(yǎng)溫度下外加劑對水泥基材料體積穩(wěn)定性的影響[J];混凝土;2007年03期
5 閆麗坤;;冬季蒸養(yǎng)溫度控制對混凝土構(gòu)件質(zhì)量影響淺析[J];山西建筑;2007年01期
6 何智海;劉寶舉;;淺談蒸汽養(yǎng)護條件下水泥-粉煤灰復合膠凝材料的水化性能[J];粉煤灰;2006年06期
7 彭樹平;沈嵐;;科威特某工程預制件現(xiàn)場蒸汽養(yǎng)護施工的幾個關(guān)鍵點[J];水利水電施工;2006年03期
8 廖俊萍;礦渣微細粉商品混凝土在蒸養(yǎng)預制構(gòu)件中的應用[J];混凝土;2004年07期
9 劉寶舉,謝友均;粉煤灰-硅灰雙摻蒸養(yǎng)混凝土配制技術(shù)研究[J];粉煤灰綜合利用;2003年05期
10 劉寶舉,謝友均;蒸養(yǎng)超細粉煤灰混凝土的強度與耐久性[J];建筑材料學報;2003年02期
相關(guān)碩士學位論文 前2條
1 王曉東;裝配式大板結(jié)構(gòu)的抗震性能分析[D];中國地震局工程力學研究所;2009年
2 李敏霞;大型混凝土箱梁蒸汽養(yǎng)護工藝與溫度場研究[D];西安建筑科技大學;2006年
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