Prof J H Sharp

BSc PhD CEng FIMMM
Emeritus Professor of Ceramics

Prof J H Sharp

Address:
Department of Materials Science and Engineering
Sir Robert Hadfield Building
Mappin Street, Sheffield, S1 3JD

Telephone: +44 (0) 114 222 5504
Fax: +44 (0) 114 222 5943

Email: j.h.sharp@sheffield.ac.uk

John Sharp joined the University of Sheffield in 1967 and was Head of Department from 1995 - 1999. He was 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

His early research was concerned with chemical reactions of minerals, especially oxidation and dehydroxylation processes. This was 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.

Selected Publications

  • J I Escalante-Garcia and J H Sharp, "Variation in the composition of C-S-H gel in Portland cement pastes cured at different temperatures", J Am Ceram Soc, 82(11), 3237-3241, 1999.
  • S A Hartshorn, J H Sharp and R N Swamy, "Thaumasite formation in Portland-limestone cement pastes", Cem Concr Res, 29(8), 1331-1340, 1999.
  • R Yang and J H Sharp, "Hydration characteristics of Portland cement after heat curing?, Part I. Hydration of anhydrous phases", J Am Ceram Soc, 84(3), 608-614, 2001; Part II. "Evolution of crystalline aluminate-bearing hydrates", J Am Ceram Soc, 84(5), 1113-1119, 2001.
  • J Hill and J H Sharp, "Heat evolution in composite cements with additions of Sn(II) and Sn(IV) chlorides", Adv Cem Res, 15(2), 57-66, 2003.
  • S M Torres, C A Kirk, C J Lynsdale, R N Swamy and J H Sharp, "Thaumasite-ettringite solid solutions in degraded mortars", Cem Concr Res, 34(8), 1297-1305, 2004.