矿物掺合料对大直径桩环形护壁材料强度的影响

Influence of mineral admixture on strength of annular retaining materials fter verification for large diameter piles

青山河特大桥项目应用了一种适用于大型桥梁的新型大直径混凝土管桩基础,该大直径混凝土管桩基础最外层为护壁材料,这种护壁材料采用水下不分散混凝土,对于流动性、强度均有一定的要求,由于该材料通过掺入矿物掺合料调节其流动性,为研究矿物掺合料对于该材料的强度影响,有利于强度把控,本文设计了水下不分散砂浆单掺及全因子试验,采用陆上成形和水下成形两种方式,分别测定水下不分散砂浆的7d强度、28d强度,水陆强度比,通过单掺试验分析了矿物掺合料对强度的影响,设计全因子试验并借助mintable分析了不同矿物掺合料掺量之间的交互效应,并将数据拟合,得到了相关强度公式,经验证后可信度较高,给出了3种掺合料复掺时的最佳掺量,方便掺矿物掺合料的水下不分散混凝土的强度控制。

The Qingshanhe Super Large Bridge Project has applied a new type of large diameter concrete pipe pile foundation suitable for large bridges.The outermost layer of the large diameter concrete pipe pile foundation is a wall protection material,which uses underwater non dispersive concrete and has certain requirements for fluidity and strength.Due to the fact that the material regulates its fluidity by adding mineral admixtures,in order to study the impact of mineral admixtures on the strength of the material,In order to control the strength,this paper designed a single and full factor test for underwater non dispersive mortar,using two methods of onshore molding and underwater molding to measure the 7-day strength and 28-day strength of underwater non dispersive mortar,as well as the water land strength ratio.Through a single mixing test,the impact of mineral admixtures on the strength was analyzed.A full factor test was designed and the interaction between different mineral admixtures was analyzed with the help of Mintable,and the data were fitted,The relevant strength formula has been obtained,which has been verified to be highly reliable.The optimal dosage of three admixtures for composite mixing is given to facilitate the strength control of underwater non dispersive concrete mixed with mineral admixtures.