Geopolymer concrete is an emerging construction material that uses a by-product material such as fly ash to completely replace the ordinary Portland cement. This material is being studied extensively and shows promise as a greener substitute for ordinary Portland cement. This paper evaluates the bond strength and development length of reinforcements embedded in geopolymer concrete with reinforcing steel using pull-out tests. The test according to EN 10080 was carried out on 27 specimens for three kinds of geopolymer concrete of 20, 30 and 40 MPa compressive strength and 10, 16 and 35 mm diameter reinforcing bars. The tests show that the bond strengths in geopolymer concrete were decreased as the diameter of reinforcement increased as in ordinary concrete and the values were greater than those in ordinary concrete. Also, the bond-slip curves were obtained which have similar shape with those of ordinary concrete. The equation for the determination of development length based on this experiment was proposed.

Researches on Ultra High Performance Concrete (UHPC) have been conducted worldwide owing to its outstanding durability and strength performances compared to normal concrete. This paper experimentally investigates the bond properties of reinforcements embedded in UHPC using direct pull-out tests. The specimens were prepared for various compressive strength levels of 120, 150, and 180MPa, diameters of reinforcements of 13, 16, 19, 22 and 25mm, cover to bar diameter ratios and bonded lengths. The influences of each test variable on bond properties are examined and may be a useful data for design and analysis of UHPC structures.

The various push-out tests have been performed to investigate the load carrying capacity and ultimate behavior of headed studs in UHPC (Ultra High Performance Concrete), which has high compressive and tensile strength as well as high durability compared to ordinary concrete. The test program included the studs with a diameter of 16mm and 22mm for various aspect ratios (height to depth ratio of a stud) and cover depths. This paper presents the main results of the experimental investigations.

Researches on Ultra High Performance Concrete (UHPC) have been conducted worldwide owing to its outstanding durability and strength performances compared to those of normal concrete. The application of UHPC to prestressed concrete structures, which may seem to be the most appropriate and beneficial, may result significant improvement in the design of anchorage zones due to its high compressive and tensile strength. The size of anchorage blocks and amounts of reinforcements may be reduced drastically. This paper examines the stress magnitudes and distributions of post-tensioned anchorage zones using UHPC which have nominal compressive strength levels of 120, 150 and 180 MPa respectively, by FE analysis. The analytic results are verified with the existing experimental work of 180MPa UHPC. It can be concluded that the use of UHPC to post-tensioned members gives significant reduction of anchorage zone size and no reinforcements are required.