Background: The use of supplementary cementitious materials, such as fly ash, silica fume, slag, and natural pozzolans, in concrete bridge decks has become a widely accepted practice by many state highway agencies, primarily due to the favorable effects on durability. Also, a great deal of research has been performed on properties of concrete containing one or more supplementary cementitious materials. However, research has not provided clear conclusions concerning the optimum use of these materials to reduce permeability and cracking and thus enhance durability.

Research is needed to develop a methodology for designing concrete mixtures containing supplementary cementitious materials used in concrete bridge decks. This methodology will help highway agency personnel to specify the materials and proportions or performance criteria that will ensure long-term performance of concrete bridge decks.

Objective: The objective of this research is to develop a methodology for designing hydraulic cement concrete mixtures incorporating supplementary cementitious materials that will result in enhanced durability of cast-in-place concrete bridge decks. The research shall consider the use of fly ash, silica fume, slag, and natural pozzolans both singularly and in combination.

Status: The research has been completed. The final report has been received; copies have been distrubuted to sponsors (state deartments of Transportation), FHWA, and AASHTO.

Product Availability: The guidelines developed in this research has been published as NCHRP Report 566 https://onlinepubs.trb.org/onlinepubs/nchrp/nchrp_rpt_566.pdf.