Binders manufactured using a blend of gypsum, ground granulated blast furnace slag and Portland cements are technically viable and possess considerable environmental and economic advantages when compared to binders manufactured using Portland cement alone. As such, the evaluation of binders made from these materials offers a promising research focus in the quest to produce technically sound, environmental and economical binders for specialist uses as an alternative to traditional concrete binders of higher carbon footprint. The aim of the test programme was to investigate the viability of a series of binders designed to fulfil particular user needs while having significantly decreased carbon footprints.Two distinct series of binders were designed; the dominant ingredient in the first was calcium sulfate while in the second it was ggbs. Potential applications for both series of binders were considered and the strength development of each binder was analysed. In 2 addition, the effect of water on the gypsum-based binders was analysed, as was the sulfate resistance of the ggbs-based binder.The results of the laboratory tests carried out were varied. For the calcium sulfatebased binders, those manufactured using anhydrite II as the dominant ingredient were found to achieve highest strengths. However these binders were found to be particularly susceptible to moisture-induced deterioration. For the ggbs-based binders, it was found that the early strength development was improved by the addition of small quantities of anhydrite II and gypsum. The strengths and sulfate resistance at later ages remained unaffected. These binders may have significant potential in situations were early strength development is a requirement.

Anaerobic corrosion of steel reinforcement is rarely reported and limited literature is available on the subject. Corrosion of steel is an electrochemical process requiring a supply of oxygen in the presence of moisture. Steel corrosion product usually occupies a much larger volume than the un-corroded steel resulting in cracked or spalled concrete. If the supply of oxygen is restricted, black rust may be formed by the process of anaerobic corrosion. Black rust is not expansive, which makes it particularly difficult to detect in reinforced concrete. This paper presents a case study of anaerobic corrosion in the Mizen Bridge, together with an in-depth review of anaerobic corrosion of reinforcement in concrete, outlining black rust formation, characteristics and detection methods.

Partial replacement of high clinker content cements by Ground Granulated Blastfurnace Slag (GGBS) can reduce the carbon footprint of concrete, with consequent benefits in respect of sustainable construction. Furthermore a state-of-the-art report indicated that use of GGBS as a binder replacement may increase the fire resistance of concrete. If so this could lead to thinner sections in fire compartment elements, especially non-loadbearing walls, leading to further gains in respect of sustainable development. Concrete is considered an effective material in protecting against the detrimental effects of fire in structures. However, exposure to high temperatures can degrade concrete performance. Fire resistance performance is typically defined relative to three failure criteria: load bearing resistance (R), insulation (I) and integrity (E). Heat transfer is a critical element of insulation and integrity performance.An experimental programme was developed to examine the potential beneficial influence of GGBS on fire resistance by examining the heat transfer performance of concrete, with and without GGBS. Test panels of concrete were subjected to heating to high temperatures. The panels included either limestone or sandstone aggregate, and a binder content of either CEM II/A-L only or a CEM II/A-L and GGBS combination at a cement replacement level of 70%. Concrete panels were heated in accordance with the standard fire curve of Eurocode 2.It was found that the heat transfer behaviour was in line with published data in the Eurocode for structural fire design. When exposed to elevated temperatures, such as those experienced in a fire situation, the performance of concrete containing GGBS exhibited a marginally lower rate of heat transfer than that of CEM II/A-L concrete. This resulted in a marginal improvement in the separating function (EI) performance. The marginally lower transfer of heat exhibited by GGBS concrete improved performance in terms of EI, such that a 5% reduction in the thickness of reinforced concrete separating elements could be considered. In addition, increased resistance to the effects of actions on a member, designed in accordance with the 500˚C isotherm 'simplified' method detailed in Eurocode 2, demonstrated a potential increased resistance of up to 10%.

Bridge-management systems (BMSs) allow bridge owners to assess the condition of their bridge stock. However, not all BMS packages have the capability to formulate network-level bridge-rehabilitation investment strategies. This research has developed a decision-support system for bridge owners in the selection of the best strategy for bridge rehabilitation at the network level. The basis of the research is an available data set of 1367 bridge-inspection records for County Cork, Ireland, that has been prepared to the Eirspan BMS inspection standard. The developed system consists of a project-prioritisation procedure that builds on previous research, a methodology for the calculation of a deterioration rate based on published bridge data and, through the use of efficiency and effectiveness indicators taken from international practice, proposes the concept of system performance in the identification of annual rehabilitation investment requirements to achieve full bridge-stock rehabilitation.

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