全再生细骨料的制备及其在砂浆和混凝土中的应用研究

发布时间：2018-01-02 13:30

本文关键词：全再生细骨料的制备及其在砂浆和混凝土中的应用研究　出处：《华南理工大学》2014年硕士论文　论文类型：学位论文

【摘要】：我国目前正在进行大规模的基本建设和城镇化，面临着建筑垃圾处理和建筑材料不足两大问题。一方面，城市的更新改造和建设每年产生大量的建筑垃圾，现在一般的处理手段是填埋，这种方法不仅浪费巨大的人力物力，而且占用大量土地资源。另一方面，砂石等建筑材料用量巨大，且砂石是不可再生资源，过量开采会对人类生存环境造成破坏，不符合可持续发展的原则。将废弃混凝土等建筑垃圾制备成混凝土所需的再生粗/细骨料能有效地解决这两方面的问题。但传统的再生粗/细骨料由于含有砂浆，其对混凝土性能有不良影响，难以有效利用。特别是再生细骨料通常只能作为填方使用，难以取代河砂和机制砂作为细骨料制备砂浆和混凝土使用。为了提高再生细骨料的质量，以便其能在砂浆和混凝土中应用，华南理工大学研发了把建筑垃圾全部破碎为再生细骨料的全再生细骨料技术。由于全再生细骨料中含有大量粗骨料破碎得到的机制砂，全再生细骨料的性能较传统再生细骨料有明显改善。本文在前期研究的基础上，对全再生细骨料的制备方法及其在砂浆和混凝土中应用进行了系统研究。本文主要研究内容和研究结论如下：（1）在实验室配合使用颚式破碎机和圆盘整形机，制备了5个系列共15种全再生细骨料。通过对各种工艺制作的全再生细骨料性能对比，以优良的颗粒级配作为主要筛选条件，并结合表观密度、堆积密度、堆积空隙率、微粉含量等指标，得到了全再生细骨料的优选制备方法为：将废弃混凝土用颚式破碎机二次破碎分筛后，将较粗粒径的部分（粒径2.36m以上）利用圆盘整形机进行整形。（2）通过对全再生细骨料与传统整形再生细骨料、传统再生粗骨料制细骨料、石灰岩机制砂、河砂等细骨料物理性能的对比，发现全再生细骨料有效地提高了再生细骨料的物理性能，其拥有较好的颗粒级配，表观密度较高而且饱和面干吸水率较低，各项性能上都比传统整形再生细骨料要好，但仍与石灰岩机制砂和河砂存在一定差距。（3）针对全再生细骨料吸水率较高这一特性，设计了全再生细骨料提前24h预饱水、搅拌前全再生细骨料预饱水3min和常规这三种全再生细骨料砂浆搅拌制度，研究其对砂浆工作性能的影响。结果表明，全再生细骨料吸水速度较快，全再生细骨料在砂浆中应用时可以采用常规搅拌制度。（4）使用全再生细骨料、传统整形再生细骨料、传统再生粗骨料制备的再生细骨料、石灰岩机制砂和河砂作细骨料，用灰砂比1：4，并调节用水量配制相同稠度砂浆，研究全再生细骨料对砂浆性能的影响。结果表明，全再生细骨料制备的砂浆工作性能、力学性能明显优于较传统整形再生细骨料，而且力学性能优于河砂砂浆；全再生细骨料砂浆均能满足《预拌砂浆》（GB/T25181-2010）中的各项要求，能全取代河砂和机制砂制备砂浆。（5）研究了附加水对全再生细骨料制备的混凝土性能的影响。结果表明，，在相同配合比下，全再生细骨料混凝土的初始坍落度比河砂混凝土低，强度比河砂混凝土高，而通过增加附加水能提高其工作性能，但强度下降。（6）使用全再生细骨料、传统整形再生细骨料、传统再生粗骨料制备的再生细骨料、石灰岩机制砂和河砂作细骨料，用三种配合比制作混凝土，研究全再生细骨料对混凝土性能的影响。结果表明，全再生细骨料制备的混凝土工作性能、力学性能均优于传统再生细骨料制备的混凝土；使用同等胶凝材料用量和水灰比时，其强度比河砂混凝土高；能够使用全再生细骨料全取代河砂和机制砂制备混凝土。
[Abstract]:At present , large - scale capital construction and urbanization are being carried out in our country , and there are two major problems of construction waste disposal and lack of construction materials . In one aspect , the renovation and construction of the city produces a large amount of construction waste each year , and the general treatment measures are landfill . In the other hand , the construction materials such as sand and stone are huge , and sand and stone are non - renewable resources , and the excessive exploitation can cause damage to the human existence environment and do not conform to the principle of sustainable development . The recycled coarse / fine aggregate such as waste concrete can effectively solve the problems of the two aspects , but the traditional recycled coarse / fine aggregate has bad influence on the performance of the concrete due to the containing mortar , and is difficult to be effectively utilized , particularly the recycled fine aggregate can only be used as a filling , and the sand and the mechanism sand are difficult to replace as fine aggregate to prepare mortar and concrete . In order to improve the quality of recycled fine aggregate , so that it can be applied in mortar and concrete , South China University of Science and Technology has developed all - recycled fine aggregate technology to crush the whole recycled fine aggregate into recycled fine aggregate . The main research contents and conclusions are as follows : ( 1 ) A total of 15 total recycled fine aggregates were prepared by using jaw crusher and disc - shaped crusher in laboratory . The optimum preparation method of fully recycled fine aggregate was obtained by using fine particle grading as the main screening condition and combining apparent density , bulk density , stacking porosity and micro powder content . ( 2 ) By comparing the physical properties of fine aggregate , such as fine aggregate , fine aggregate , limestone mechanism sand , river sand and other fine aggregate of recycled fine aggregate and traditional recycled fine aggregate , it is found that the total recycled fine aggregate effectively improves the physical properties of recycled fine aggregate . It has better particle size distribution , higher apparent density and lower dry water absorption of saturated surface , which is better than that of traditional plastic recycled fine aggregate , but still has a certain gap with limestone mechanism sand and river sand . ( 3 ) According to the characteristics of high water absorption rate of full - recycled fine aggregate , the full - recycled fine aggregate is designed to be pre - saturated in advance for 24h , pre - saturated with pre - saturated water for 3 minutes before stirring , and the conventional three kinds of all - recycled fine aggregate mortar mixing system is designed to study its influence on the working performance of mortar . The results show that the water absorption rate of full recycled fine aggregate is fast , and the conventional stirring system can be used in the application of fully recycled fine aggregate in mortar . ( 4 ) Use full recycled fine aggregate , traditional plastic recycled fine aggregate , recycled fine aggregate prepared from traditional recycled coarse aggregate , limestone mechanism sand and river sand as fine aggregate , use ash sand ratio of 1 : 4 , and adjust water consumption to prepare the same consistency mortar . The results show that the mortar working performance and mechanical property of fully recycled fine aggregate are better than those of traditional plastic recycled fine aggregate , and the mechanical property is superior to that of river sand mortar ; all recycled fine aggregate mortar can meet the requirements of mortar premixed mortar ( GB / T25181 - 2010 ) , and can fully replace sand and mechanism sand to prepare mortar . ( 5 ) The influence of additional water on the properties of concrete prepared by fully recycled fine aggregate is studied . The results show that the initial slump of full recycled fine aggregate concrete is lower than that of river sand concrete under the same mixing ratio , and the strength is higher than that of river sand concrete , but the working performance is improved by adding additional water , but the strength decreases . ( 6 ) Using recycled fine aggregate , traditional plastic recycled fine aggregate , recycled fine aggregate prepared from traditional recycled coarse aggregate , limestone mechanism sand and river sand as fine aggregate , the effect of full recycled fine aggregate on the performance of concrete is studied .

【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU528;TU578.1

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