水电站泄洪隧洞抗冲耐磨混凝土施工技术研究

为解决水电站泄洪隧洞因水流流速大、水流夹砂而造成洞壁磨损快的难题,基于双江口水电站泄洪隧道工程,对抗冲耐磨混凝土的配合比设计、振捣施工工艺进行试验研究,并通过实际工程的应用对试验结果进行验证,对泄洪隧洞抗冲耐磨混凝土施工工艺进行阐述。研究结果表明,硅粉掺入后,抗冲耐磨混凝土的流动性及施工性能降低,减水剂实际掺量与设计掺量相差较大;与掺入硅粉的混凝土相比,掺入HB7-1可使抗冲耐磨混凝土施工性能大幅提高,且用水量降低9~10 kg/m^(3);添加HDC高性能掺合料时,混凝土强度增加20%以上;采用最佳振捣参数组合的抗冲耐磨混凝土浇筑的泄洪洞边墙表面平整度、气泡数量及表观质量均可达到预期效果,对类似工程具有借鉴意义。

In order to solve the problem of fast wear of the tunnel wall caused by high flow velocity and sand inclusion in the spillway tunnel of hydropower station,based on the flood discharge tunnel project of Shuangjiangkou Hydropower Station,the proportion design and vibration construction technology of anti-impact wear-resistant concrete were studied,and the test results were verified by the application of practical engineering.The construction technology of anti-impact and wear-resistant concrete for spillway tunnel is described.The results show that the fluidity and construction performance of impact-resistant and wear-resistant concrete are decreased after silica powder is added,and there is a great difference between the actual dosage of water-reducing agent and the designed dosage.Compared with concrete mixed with silica powder,HB7-1 can greatly improve the construction performance of impact-resistant and wear-resistant concrete,and reduce the water amount by 9~10 kg/m^(3).When HDC high-performance admixture is added,concrete strength increases by more than 20%.The surface smoothness,the number of bubbles and the apparent mass of the side wall of the spillway tunnel poured by the anti-impact wear-resistant concrete with the best combination of vibrating parameters can achieve the expected results,which can be used as a reference for similar projects.