No abstract

The development of a rapid, non-parametric, and slightly conservative predictor for the estimation of probable weight loss in the standard Building Research Establishment sodium sulphate crystallisation test, and hence of estimated limestone durability class, based on [Porosity Saturation ] 0.5 is described. The time saving offered by application of the look-up tables provided here reduces the 3–4 weeks required for the Building Research Establishment crystallization weight loss test to a matter of hours and offers considerable practical advantage for rapid assessment of the suitability of limestone building stones quarried abroad (e.g. in Jordan) for use in the salt weathering conditions of the UK. However, there is a relatively large variance associated with this estimator (particularly when the microporosity coefficient exceeds 0.65) and in critical cases it should be followed up by confirmatory use of the standard crystallization weight loss test.

Gassifier slag (GS) is a potential new cement replacement material which is intermediate in composition between granulated blastfurnace slag (GBFS) and pulverized fuel ash (P FA). Three GSs have been blended with an ordinary Portland cement (OPC) and a sulphate-resisting Portland cement (SRPC) , and comparisons made with a G BFS and a P FA blended with the two cements. Several techniques have been used to investigate the slag-cement interactions in both the early and later stages of hydration. The results indicate that, like GBFS, GS cements show latent hydraulic activity, particularly in the early stages of hydration, while, as with PFA, pozzolanic activity dominates in the later stages.