煤矸石矿物掺合料对高强混凝土性能影响试验研究
发布时间：2018-11-22 16:20
【摘要】：高效减水剂和优质活性矿物掺合料的掺入,促使混凝土可以在较低水胶比的条件下形成高强度混凝土。而我国优质掺合料资源有限,已经突显出短缺现象,开发新的掺合料迫在眉睫。煤矸石富含硅、铝质成分,经过一定的活化处理后具有一定的活性和微骨料效应,使其制备优质矿物掺合料成为可能。目前对于煤矸石作为矿物掺合料的研究尚不成熟,尤其是对未燃煤矸石的研究更为少见。本文是国家自然科学基金委员会与神华集团有限公司联合资助项目—“煤矸石在水泥和混凝土中资源化利用关键科学问题研究”(U1261122)中的子项目,所有研究成果都是在该基金的资助下完成并取得的,主要研究成果如下：(1)胶砂强度评价表明：粒径≤2.5mm的未燃煤矸石颗粒经过煅烧研磨处理后,按30%取代42.5水泥制备的煅烧煤矸石粉-水泥胶砂强度达到42.91MPa,活性指数高达0.89,优于I级粉煤灰,稍逊于S95矿粉；(2)不同品种矿物掺合料复掺的正交试验表明：粉煤灰对于混凝土拌合物工作性改善程度最大；煤矸石掺合料与硅灰复掺时,在有聚羧酸系减水剂配合使用的条件下,同样可以配制出流动性与粉煤灰-硅灰复掺相近的效果；不同种类矿物掺合料对高强混凝土强度的贡献程度为：煅烧煤矸石粉自燃煤矸石粉I级粉煤灰,几种掺合料均对混凝土长期强度有不同程度的提高,其中煅烧煤矸石粉与硅灰复掺对混凝土长期强度的提高贡献最大；(3)C70煅烧煤矸石粉掺合料的单因素对比试验表明：煅烧煤矸石粉掺量对于混凝土拌合物初始坍落度影响较小,拌合物经时损失随掺量增加有递增趋势；煅烧煤矸石粉掺量为10%时混凝土7d强度最高,随着掺量的增大强度有所降低；混凝土28d强度随掺量的递增表现为先升高后降低的趋势,掺量在20%时强度最高；煅烧煤矸石粉掺量在20%以内时,对混凝土56d强度仍有提高作用；煅烧煤矸石粉的掺入能够显著提高混凝土的抗氯离子渗透性能,掺入量在30%以内时,混凝土28d、56d电通量随掺入量递增大幅度下降：煤矸石矿物掺合料混凝土具有极佳抗冻融能力,煅烧煤矸石粉的掺入,能够提高混凝土抗冻融性,经过1500次冻融循环,混凝土表面仍无明显剥蚀脱落现象,质量和动弹性模量损失率都满足规范要求。研究结果表明,单掺煅烧煤矸石粉配制高强混凝土可行。
[Abstract]:The addition of high efficiency water reducing agent and high quality active mineral admixture can promote the formation of high strength concrete under the condition of low water / binder ratio. But our country high quality admixture resource is limited, already highlighted the shortage phenomenon, the development new admixture is imminent. Coal gangue is rich in silicon and aluminum. After certain activation treatment, it has certain activity and microaggregate effect, which makes it possible to prepare high quality mineral admixture. At present, the study of coal gangue as mineral admixture is still immature, especially for unburned coal gangue. This paper is a sub-project of the National Natural Science Foundation Committee of China and Shenhua Group Co., Ltd., which is a joint project of "study on key Scientific problems of Utilization of Coal gangue in cement and concrete" (U1261122). All the research results were completed and obtained with the aid of the fund. The main research results are as follows: (1) the evaluation of the strength of cement sand shows that the unburned coal gangue particles with diameter 鈮，
本文编号：2349876
[Abstract]:The addition of high efficiency water reducing agent and high quality active mineral admixture can promote the formation of high strength concrete under the condition of low water / binder ratio. But our country high quality admixture resource is limited, already highlighted the shortage phenomenon, the development new admixture is imminent. Coal gangue is rich in silicon and aluminum. After certain activation treatment, it has certain activity and microaggregate effect, which makes it possible to prepare high quality mineral admixture. At present, the study of coal gangue as mineral admixture is still immature, especially for unburned coal gangue. This paper is a sub-project of the National Natural Science Foundation Committee of China and Shenhua Group Co., Ltd., which is a joint project of "study on key Scientific problems of Utilization of Coal gangue in cement and concrete" (U1261122). All the research results were completed and obtained with the aid of the fund. The main research results are as follows: (1) the evaluation of the strength of cement sand shows that the unburned coal gangue particles with diameter 鈮，
本文编号：2349876
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