波浪形纤维混凝土滑模摊铺施工应用与抗裂测试

Application and crack resistance testing of wave shaped fiber reinforced concrete slipform paving construction

采用波浪形纤维混凝土,就其滑模摊铺施工应用与抗裂测试进行了研究。钢纤维混凝土配合比设计参数选用:水灰比0.46,钢纤维体积率0.85%~1.25%,砂含量为818 kg/m^(3)。增设钢纤维分散装置的操作是由钢纤维混凝土搅拌机来完成,在该设备的作用下使水泥、钢纤维、粗细集料拌均匀,然后将水加入后完成湿拌,时间控制为2 min,另外还要注意的是对于搅拌量的要求比较严格,要将其控制在额定搅拌量的85%以内。钢纤维混凝土拌合物在搅拌机内完成制作,将其卸出后进行摊铺,整个过程要在45 min内完成。对振捣频率的要求是必须超过普通混凝土,以此来保障摊铺过程作业的连续性。坍落度为30 mm时,松铺系数控制为1.1,随天气状况,控制布料及卸料长度为5~10 m。在后裂缝阶段可以看到纤维混凝土材料相比较于素混凝土材料,变形能力和断裂能均达到较高水平。

Adopts the sliding mode paving technology to study its application and crack resistance testing in the construction of wavy fiber reinforced concrete.The design parameters for the steel fiber reinforced concrete mix ratio are selected as follows:water cement ratio of 0.46,steel fiber volume ratio from 0.85%to 1.25%,and sand content of 818 kg/m^(3).The steel fiber concrete mixer is equipped with a steel fiber dispersion device to evenly mix cement,steel fibers,and coarse and fine aggregates.Water is added for wet mixing,and the mixing time is 2 minutes.The mixing amount at a time cannot exceed 85%of the rated mixing amount.The unloading of steel fiber concrete mixture from the mixer to the completion of paving should not exceed 45 minutes.The vibration frequency should be higher than that of ordinary concrete paving to ensure the continuity of the paving process.When the slump is 30 mm,the loose laying coefficient is controlled at around 1.1.Depending on the weather conditions,the length of the fabric and discharge is controlled between 5 m and 10 m.In the post crack stage,it can be seen that fiber reinforced concrete materials have higher levels of deformation capacity and fracture energy compared to plain concrete materials.