Dry Shrinkage Property of BFRP Reinforced Ecological High Ductility Concrete

Abstract

Ecological high ductility concrete (Eco-HDC) has an excellent tensile property, thus can be used to cast bridge jointless link slab. To avoid the crack problem caused by the large shrinkage of Eco-HDC material, BFRP bar is selected as a kind of anti-cracking bar. The purpose of this study is to obtain the cover thickness of BFRP bar for the structural design on the basis of shrinkage analysis of BFRP bar reinforced Eco-HDC. The effect of cover thickness on dry shrinkage of BFRP bar reinforced Eco-HDC was investigated, and the comparative study on shrinkage between BFRP bar reinforced Eco-HDC and plain Eco-HDC was also considered. Results indicate that as the curing age increases, the dry shrinkage, of BFRP bar reinforced Eco-HDC and plain Eco-HDC increase, and the compressive strain of BFRP bar also shows an increasing trend. Specifically, the increasing trend shows an faster speed with a curing ages of 1-7 d, then the increasing speed slows down. In addition, as the cover thickness decreases, the shrinkage of BFRP bar reinforced Eco-HDC increases, and the strain of BFRP bar also increases as a result of the obvious constraint effect. A minor difference of BFRP bar strain is ovserved at the ages of 45 d. The moist curing of bride jointless link slab with curing age of 7 d is suggested during its construction, and the cover thickness of 25 mm is screened for the structural design.

Keywords

• ecological high ductility concrete (eco-hdc)
• bfrp bar
• dry shrinkage
• cover thickness
• strain of bfrp bar