Creep and residual properties of cracked macro-synthetic fibre reinforced concretes

Abstract

This study analysed the creep behaviour of five concretes incorporating 0·5% by volume of four macro-synthetic fibres (MSFs) and one steel fibre. After 28 d moist curing, prisms were pre-loaded up to a crack opening of 0·5 mm and held for 90 d in three different environments -ambient laboratory air, seawater at 45°C and air flow at 45°C.Sustained loads were then applied on three specimens from each group while the other prisms remained unloaded.The remaining residual capacity was evaluated by bending tests. It was concluded that the residual capacity of cracked MSF concretes is not affected by long-term loading.

Long-term behavior of cracked fiber reinforced concrete under service conditions

“…From comparative studies, flexural creep behavior was found influenced by both the fiber type and the load level [4], in this case by using round panels made of shotcrete which were pre-cracked up to 3.5 mm. It was stated that the fiber type and environmental conditions can affect creep behavior and the residual response of SFRC [18]. Similar creep behavior was observed by using three-and four-point loading configurations [19].…”

“…Also, variations in load scheme (threepoint bending tests (3PBT) or four-point bending tests (4PBT)), pre-cracking process, and load level and time period, among others factors, has been carried out. Concerning experimental research on flexural creep behavior, the literature found in international journals reports important contributions from research on steel FRC (SFRC) [2,4,[16][17][18][19][20].…”

“…Some studies were carried out introducing large initial crack widths (0.5-2 mm in beams [2,16,[18][19][20], and 3.5 mm in round panels [4]), and also high sustained load levels were applied in relation to cracking load (more than 90% in some cases [2], commonly about 50-70% [16,19], and lower than 50% in few cases [20].…”

Influence of Fibre Reinforcement on the Long-Term Behaviour of Cracked Concrete

“…The mechanical behaviour of fibre reinforced concrete (FRC) has been widely studied over the past decades [3], and important advances have been achieved regarding the residual strength characterization and applications of FRC [2]. On the other hand the analysis of flexural creep behaviour of cracked FRC elements is a relatively new topic which has not been entirely researched yet.…”

“…Although residual strength parameters are applied in structural design, the knowledge of the long-term behaviour of FRC in cracked conditions is limited to a few reports on the subject [1][2][3]5,[7][8][9].…”