Using seawater and/or recycled coarse aggregates (RCA) for concrete mixing is deemed advantageous from a sustainability perspective.This paper reports on the results of an experimental study on fresh and hardened properties of concrete mixed with seawater and RCA.Three concrete mixtures were investigated, namely, Mix A (traditional concrete), Mix B (concrete made with seawater), and Mix C (concrete made with seawater and RCA).It was concluded that the use of seawater and/or RCA had a notable effect on fresh concrete properties.Mix B concrete showed a slightly lower strength performance than that of Mix A (<15%), whereas the strength of Mix C concrete had a significant drop (~30%) compared to the reference (Mix A).The permeability performance of hardened concrete for Mixes A and B was similar, whereas Mix C concrete showed 60% increase in water absorption and 100% increase in chloride permeability as compared to Mix A.
This paper presents laboratory tests on a bond-type anchorage system and a full-scale ground anchor with fiber-reinforced polymer 9-bar tendons. A cement-based mortar filled steel tube was used to simulate a rock mass environment. Resistance strain gauges, fiber optic sensors, embedded strain gauges, and linear variable displacement transducers were used to monitor the behavior of the anchor and to study load transfer mechanism of the tendon to surrounding rock mass. The test results show that the developed bond-type anchorage performs well for post-tensing applications with the tendons. The tested anchor presents an acceptable tensile behavior for each loading stage investigated (up to a load level of 0.6ffu , where ffu =guaranteed capacity of the tendon) in accordance with existing codes. The anchor is similar in strain distribution profile to conventional steel anchors, except giving a shorter load transfer length. It is expected that the anchor require a minimum anchor bonded length of 2,000mm with plain cement grouts.
