Professor John H Sharp


Department of Materials Science and Engineering

Emeritus Professor of Ceramics
+44 114 222 5504

Full contact details

Professor John H Sharp
Department of Materials Science and Engineering
Sir Robert Hadfield Building
Mappin Street
S1 3JD

John Sharp joined the University in 1967 and was Head of Department from 1995 - 1999, Chairman of the Ceramic Industry Division of the Institute of Materials from 1999-2002, and a member of the HEFCE Research Assessment Exercise Panel (2001) in Metallurgy and Materials. He was awarded the Kroll Medal and Prize for Materials Chemistry by the Institute of Materials, Minerals and Mining in 2003.

Research interests

John's early research was concerned with the chemical reactions of minerals, especially oxidation and dehydroxylation processes. This extended after coming to Sheffield to include solid-state reactions relevant to ceramics, particularly reactions between carbonates and oxides to form ferrites, titanates and, more recently, superconducting cuprate ceramics.

A major current interest is in the chemistry of the hydration of cements and plasters. Research has been carried out into lime plasters and composite cements, based on the partial replacement of Portland cement by waste products such as slags and ashes. Particular attention has been given to special cements, including refractory calcium aluminates, acid-base reaction cements and calcium sulfoaluminate cements. The effect of temperature and the incorporation of admixtures on the setting behaviour of calcium aluminate cements has been thoroughly investigated. Durability studies are in progress into the formation of delayed ettringite and thaumasite in Portland cement systems. The hydration products formed in various magnesia-phosphate systems have been identified and relations between their microstructure, mechanical properties and durability have been investigated.

Prof Sharp is actively involved in the Immobilisation Science Laboratory examining the long-term stability of intermediate-level nuclear waste materials stored in composite cements such as Portland-cement-blast furnace slag (1:9). Current research involves encapsulation of flocs based on iron hydroxide and barium carbonate, and the corrosion of various metals stored in highly alkaline conditions. Another current interest is in thermodynamic modelling of the behaviour of trace elements in cement kilns.