Capillary Transport of Water in Cracked and Non-cracked UHPFRC Specimens

Ana Mafalda Matos, Sandra Nunes, JosÚ L. Barroso Aguiar

Journal of Advanced Concrete Technology, 17, 244-259, 2019

The primary goal of the present paper is to investigate the influence of cracking on water transport by capillary suction of UHPFRC. Prismatic specimens were firstly loaded under four-point bending up to specific crack open displacement (COD). Target COD, under loading, was varied between 200 and 400 μm, in steps of 50 μm. After unloading, a COD recovery was observed with residual COD ranging between 116-334 Ám and 75-248 μm for UHPFRC-1.5% and UHP-FRC-3.0% specimens, respectively. The crack pattern created was characterised (number of cracks and crack width) before capillarity testing. Sorptivity results of cracked UHPFRC-1.5% and UHPFRC-3% specimens remained in the range of 0.024 to 0.044 mg/(mm2.min0.5), which are about 2 to 4 times higher than the sorptivity results of non-cracked UHPFRC specimens. However, the maximum sorptivity observed on cracked UHPFRC is relatively low as compared to typical sorptivity results found in good quality conventional concrete or engineered cementitious composites (ECC).

This article is about the experimental investigation of the water adsorption (due to capillary suction) in damaged and undamaged UHPFRC, and gives interesting insights on the sorptivity behavior of UHPFRC. The study is innovative and interesting since the durability analysis of this materiel is very important for sake of its practical applications. (Reviewers)