摘要
预应力混凝土桥梁建设过程中,由于孔道压浆工艺或水泥浆配合比的原因使预应力孔道内有游离水的存在,造成沿孔道方向冻胀开裂。裂缝的存在增加了混凝土的渗透性,使钢筋产生锈蚀,影响结构耐久性,很多桥梁使用寿命达不到设计年限。因而预应力混凝土桥梁孔道内压浆不密实、泌水是影响结构的极限承载能力和结构的耐久性的重要因素之一。杜绝浆体泌水,配合比的优化即是摆在广大试验人员面前重要任务。本文结合富锦至绥滨松花江公路大桥工程建设实际,介绍在水泥浆中掺入亚硝酸钙来优化浆体。通过交替冷冻和长期冷冻试验,得出的结论是:消除孔道内的游离水和促进浆体早凝、早强是提高抗冻性的途径之一。
In the construction of pre-stressed concrete bridge,the free water in pre-stressed duct because of duct grouting technology or cement mortar mixture ratio usually creates heave and dehiscence along the passageway direction.The existence of crack can increase the concrete permeability,cause the corrosion of steel bar,and affect the structure durability.Thus,the service life of many bridges cannot achieve the design-age limit.Non-compact of grouting in pre-stressed concrete bridge duct and bleeding is one of the important factors which affecting the structure of the ultimate bearing capacity and durability of the structure.Prevent cement slurry bleeding,optimization of mix proportion is important task of our test personnel.This article unifies Fujin to the suibin Songhua River road bridge engineering construction reality,introduced mixes the calcium nitrite in the cement mortar to optimize the hydromass.By alternate freezing and long-term frozen tests,came to the conclusion：Elimination of free water in the duct and promote slurry early setting,early strength is one of the ways of improving frost resistance.
出处
《森林工程》
2013年第4期120-123,共4页
Forest Engineering
基金
黑龙江省交通厅重点科技项目
关键词
亚硝酸钙
孔道压浆
泌水
抗冻性
calcium nitrite
duct grouting
bleeding
frost resistance
