No-cement eco-binder as a potential material for bridge construction

This study proposes a new type of no-cement ecobinder which could serve as a potential material for bridge construction to facilitate its safety, maintenance and management. Such cement is denoted as the SFC binder and fabricated by a mixture of three industrial wastes of ground granulated blast furnace slag (S), Class F fly ash (F), and circulating fluidized bed combustion fly ash (C). Experimental results showed that the SFC binder illustrated significantly low heat evolution during hydration compared to that of ordinary Portland cement (OPC). The fresh self-compacting concrete (SCC) produced with the optimized mix proportions of SFC binder (SFC-SCC) was reported to have excellent flowability and filling ability. The hardened SFC-SCC specimens had compressive strength high enough to be applicable for bridge construction with remarkably low drying shrinkage with equivalent 28-day compressive strength, and the confining SFC-SCC illustrated a bonding behavior with deformed steel rebar as good as that of the OPC concrete.

The bonding strength of the deformed embedded steel rebars and covering concrete made with SFC-SCC in comparison with flowable OPC hardened concrete with equivalent 28-day compressive strength is shown in Fig. 1. According to the figure, with equalized compressive strength of the hardened concrete specimens, the bonding behavior of the reinforced SFC-SCC was totally similar to that of the reinforced concrete made with flowable OPC. Such result obviously pointed out that the SFC binder can be innovative candidate for OPC alternative to be applied for structural reinforced concrete such as the bridge structure due to the as high compatibility as the OPC based reinforced concrete with similar 28-day compressive strength. Figure 1 Bonding strength of equivalent 28-day compressive strength SFC-SCC and OPC concrete specimens with deformed steel bars with diameter of 16 mm at age of 28 days. https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781315207681/cd556cd4-4dcf-4efe-8e29-56fc67b8bfbd/content/fig175_1.tif"/>