低回弹喷射混凝土技术研究
发布时间：2018-10-22 17:50
【摘要】：随着全国公路隧道、城市地铁及地下工程的迅速发展,喷射混凝土的用量呈急剧增长态势,但目前喷射混凝土由于回弹率高,不仅造成巨大的材料浪费及施工效率低下,而且还对工程质量及自然环境造成一定影响,因此研究低回弹喷射混凝土技术具有重要意义。本文在相关研究的基础上,展开了对低回弹喷射混凝土技术以下几个方面的研究。1、在喷射混凝土配合比设计时,通过引入超细矿物掺合料及回弹抑制材料改变混凝土的粘聚性及工作性,以期达到降低喷射混凝土回弹率。同时研究超细矿物掺合料复掺及回弹抑制材料对喷射混凝土评价指标的影响,并利用水泥砂浆搅拌机测试各掺合料及回弹抑制材料对砂浆屈服应力的影响。2、利用相机对喷嘴处混凝土料群进行高速抓拍,研究喷射混凝土的射流特性、射流速度及扩散角度。针对喷射混凝土射流特性,建立回弹模型,研究并分析了喷射混凝土的回弹机理。3、通过室外喷射试验,研究不同喷射工况下(喷射距离、工作压力、喷射角度等)回弹率变化,得出了最佳的工作压力、喷射距离和喷射角度。4、通过试验分别验证三种超细矿物掺合料复掺和两种高分子回弹抑制材料对降低喷射混凝土回弹率的效果。上述研究成果可为隧道支护工程中喷射混凝土的配合比设计和作业方法提供理论依据。
[Abstract]:With the rapid development of national highway tunnel, urban subway and underground engineering, the amount of shotcrete is increasing rapidly. However, because of its high rebound rate, shotcrete not only causes huge waste of materials and low efficiency of construction, but also increases rapidly. It also affects the engineering quality and natural environment, so it is of great significance to study the technology of low rebound shotcrete. On the basis of relevant research, this paper studies the following aspects of low springback shotcrete technology. 1, in the design of mix ratio of shotcrete, The cohesion and workability of concrete were changed by introducing superfine mineral admixture and springback inhibiting material in order to reduce the rebound rate of shotcrete. At the same time, the influence of superfine mineral admixture and rebound inhibiting material on the evaluation index of shotcrete was studied. The effect of concrete mixture and springback inhibiting material on the yield stress of mortar was tested by cement mortar mixer. 2. The jet characteristics, jet velocity and diffusion angle of shotcrete were studied by using camera to capture the mass of concrete at the nozzle at high speed. According to the characteristics of jet, a springback model is established, and the springback mechanism of shotcrete is studied and analyzed. 3. Through outdoor spray test, the springback rate under different spray conditions (spray distance, working pressure, spray angle, etc.) is studied. The optimum working pressure, injection distance and spray angle were obtained. 4. The effects of three kinds of superfine mineral admixtures and two kinds of polymer rebound inhibiting materials on the springback rate of shotcrete were verified by experiments. The above research results can provide theoretical basis for the mix design and operation method of shotcrete in tunnel support engineering.
【学位授予单位】：河北工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U455.4
本文编号：2287879
[Abstract]:With the rapid development of national highway tunnel, urban subway and underground engineering, the amount of shotcrete is increasing rapidly. However, because of its high rebound rate, shotcrete not only causes huge waste of materials and low efficiency of construction, but also increases rapidly. It also affects the engineering quality and natural environment, so it is of great significance to study the technology of low rebound shotcrete. On the basis of relevant research, this paper studies the following aspects of low springback shotcrete technology. 1, in the design of mix ratio of shotcrete, The cohesion and workability of concrete were changed by introducing superfine mineral admixture and springback inhibiting material in order to reduce the rebound rate of shotcrete. At the same time, the influence of superfine mineral admixture and rebound inhibiting material on the evaluation index of shotcrete was studied. The effect of concrete mixture and springback inhibiting material on the yield stress of mortar was tested by cement mortar mixer. 2. The jet characteristics, jet velocity and diffusion angle of shotcrete were studied by using camera to capture the mass of concrete at the nozzle at high speed. According to the characteristics of jet, a springback model is established, and the springback mechanism of shotcrete is studied and analyzed. 3. Through outdoor spray test, the springback rate under different spray conditions (spray distance, working pressure, spray angle, etc.) is studied. The optimum working pressure, injection distance and spray angle were obtained. 4. The effects of three kinds of superfine mineral admixtures and two kinds of polymer rebound inhibiting materials on the springback rate of shotcrete were verified by experiments. The above research results can provide theoretical basis for the mix design and operation method of shotcrete in tunnel support engineering.
【学位授予单位】：河北工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U455.4
【相似文献】
相关期刊论文 前8条
1 方勇;;卸载回弹特性及计算方法研究[J];水利与建筑工程学报;2013年04期
2 韩光滢;;喷射混凝土回弹率的快速测定[J];河北冶金;1981年02期
3 张秉璋;;横向压力影响拉弯零件回弹的研究[J];西北工业大学学报;1993年04期
4 李建民;滕延京;;土样回弹及再压缩变形特征的试验研究[J];工程勘察;2010年12期
5 王润平;浅探喷射混凝土的回弹规律[J];煤炭工程师;1998年01期
6 顾延元;如何减少喷射混凝土的粉尘和回弹[J];化工矿山技术;1980年05期
7 张淑朝;张建新;张阳;任杰东;;基坑开挖卸荷土体回弹实验研究[J];岩土工程学报;2008年S1期
8 ;[J];;年期
相关硕士学位论文 前2条
1 朱杰克;慢回弹聚氨酯泡沫塑料的制备及抗菌改性研究[D];北京化工大学;2015年
2 刘康;低回弹喷射混凝土技术研究[D];河北工业大学;2015年
，本文编号：2287879
本文链接：https://www.wllwen.com/kejilunwen/daoluqiaoliang/2287879.html
