U型-H微膨胀混凝土在砌石拱坝封拱中的应用

水工大坝使用常规混凝土，由于温度应力等多种因素往往会引起收缩开裂，进而发生渗漏，最终导致大坝使用功能降低并影响使用年限。一定比例的U型-H微膨胀剂加入常规混凝土中，水泥水化物钙矾石等受到微膨胀性结晶水化物产生的压应力挤压形成微膨胀混凝土，凝固时产生的微膨胀力使混凝土密实膨胀。本文介绍U型-H微膨胀混凝土在后垄水电站砌石拱坝封拱应用中的有关技术问题及其效果。

Application of U Type-H Micro-expansion Concrete in Masonry Arch Dam Arch Closure

Shrinkage cracking can be caused on regular concrete which is used in hydraulic dam due to a variety of factors such as temperature stress,etc.thereby leading to leakage,and finally causing function reduction on dam and influencing on service life.A certain proportion of U type H micro expander can be added into regular concrete.Cement hydrate ettringite and similar materials are squeezed by compressive stress due to micro expansion crystalline hydrates,thereby forming micro expansion concrete.Micro expansion force produced during solidification could make the concrete compacted and expanded. Related technical problems and effects of applying U type H micro expansion concrete in Houlong Hydropower Station masonry arch dam closure are introduced in the paper.