2.5.1 Structural design of HSC ACI Innovation Task Group ITG-4 is also working on the document to allow normal weight concrete with a specified compressive strength of 40 MPa or greater to be used in cast-in-place buildings constructed in reg ions where the seismic hazard is moderate to high [165]. At its 2004 Annual Meeting, […]

One benefit of SCC is that it provides improved surface appearances and aesthetics in finished concrete. Pour lines, bugholes, honeycombs, and other surface imperfections are largely reduced [164]. The fluidity of SCC as well as the elimination of vibration will result in improved aesthetics. Selection of form release agents is very important in achieving the […]

When a proper air-void system is provided, SCC can exhibit excellent resistance to freezing and thawing and to deicing salt scaling [160, 161 & 162]. It is difficult to stabilize air voids in segregating concrete. In such cases, increasing the concrete viscosity by use of a VMA or by changing the mixture proportions (through the […]

Autogenous shrinkage can be particularly high in mixtures made with relatively low w/cm, high content of cement, and supplementary cementitious materials exhibiting a high rate of pozzolanic reactivity at early age. Special attention should be given to protect the surface of SCC at early ages to minimize any desiccation. In very low w/cm mixtures, wet […]

2.4.5.1 Mechanical properties Properties of hardened SCC are expected to be similar to, or better than, those of a comparable conventional concrete mixture. Changes in mixture proportions and in fluidity can influence the hardened properties, which can diverge from what is commonly expected from conventional concrete. If specific key properties are important in a particular […]

Fiber Reinforced Concrete (FRC) requires a high degree of vibration to get good compactness. This increases the labor costs and noise pollution at the work site. Moreover, if the reinforcement is dense or the form is intricate in shape, it becomes even more difficult to place and vibrate the concrete. Unfortunately, when one tries to […]

This test evaluates the static stability of a concrete mixture by quantifying aggregate segregation. This test consists of filling a 26 in. (610 mm) high column with concrete. The column is sectioned into three pieces, as shown in Fig. 2.12. The concrete is allowed to sit for 15 minutes after placement. Each section is removed […]

The L-Box test consists of an L-shaped container divided into a vertical and horizontal section. A sliding door separates the vertical and horizontal sections. An obstacle of three reinforcing bars can be positioned in the horizontal section adjacent to the sliding door. The vertical section of the container is filled with concrete and the sliding […]

The J-Ring consists of a ring of reinforcing bar that will fit around the base of a standard ASTM C 143 slump cone. The slump cone is filled with concrete and then lifted in the same fashion as if one were conducting the slump flow test, as shown in Fig.2.10. The final spread of the […]

The slump flow test is a measure of mixture filling ability, as shown in Fig. 2.9. This test is performed similar to the conventional slump test using the standard ASTM C143-2006 [152] slump cone. Instead of measuring the slumping distance vertically, however, the mean spread of the resulting concrete patty is measured horizontally. This number […]