Effects of mineral powders on hydration process and hydration products in normal strength concrete

Abstract The use of fine material in concrete manufacture has received an increased attention during the last 10–20 years. A number of studies have been published on the influence of fillers on special types of concretes, however, the influence of fine material on ordinary concrete is less well examined. In this paper the effects of mineral powders on hydration process and hydration products of normal strength concrete were studied. Tests were carried out on concretes and cement pastes with quartz and limestone mineral powders. According to the results, heat evolution appeared to be affected by the use of mineral powders. Greater hydration heat and thus higher maturities, degrees of hydration and compressive strengths were obtained for concretes containing up to 40 wt% of added mineral powder. However, increasing the amount of mineral powder did not proportionally increase the amount of hydration heat. TGA tests on cement pastes revealed that the amount of Ca(OH) 2 was slightly lower in the mineral powder pastes but the degree of hydration was greater. The use of mineral powder to replace 10 wt% of the cement had no effect or only a small one on the amount of Portlandite and compressive strength of the pastes. However, replacing a higher amount of cement reduced the amount of Portlandite and compressive strengths notably. In addition, the results from the TGA also suggested that some of the CaCO 3 originating from the limestone was incorporated into the hydration phases. The XRD study confirmed the results obtained from the TGA. A 10 wt% cement replacement appeared to have almost no effect on the amount of Portlandite formed at the age of 28 days. However, using mineral powders to replace 30 wt% or more of the cement reduced the amount of Portlandite notably. In many of the cement pastes in which mineral powders replaced cement, the net intensity of C 3 S measured by XRD was lower than could be expected to happen as a result of mere cement replacement. It was related to a higher degree of hydration of cements with mineral powders which was additionally supported by the amount of Portlandite and the compressive strength results.

[1]  Rachel J. Detwiler,et al.  Reaction kinetics of portland cement mortars hydrated at different temperatures , 1992 .

[2]  Jean Pera,et al.  Influence of finely ground limestone on cement hydration , 1999 .

[3]  A. Kronlöf Effect of very fine aggregate on concrete strength , 1994 .

[4]  J. Gallias,et al.  THE EFFECT OF FINE MINERAL ADMIXTURES ON WATER REQUIREMENT OF CEMENT PASTES , 2000 .

[5]  B. Duthoit,et al.  Determination of apparent activation energy of concrete by isothermal calorimetry , 2000 .

[6]  F. Lea The chemistry of cement and concrete , 1970 .

[7]  Vesa Penttala,et al.  Mineral powder concrete : Effects of powder content on concrete properties , 2011 .

[8]  V. S. Ramachandran,et al.  Dependance of fineness of calcium carbonate on the hydration behaviour of tricalcium silicate , 1986 .

[9]  G. Fagerlund Chemically bound water as measure of degree of hydration: method and potential errors , 2009 .

[10]  Glykeria Kakali,et al.  Hydration products of C3A, C3S and Portland cement in the presence of CaCO3 , 2000 .

[11]  Luc Taerwe,et al.  General hydration model for portland cement and blast furnace slag cement , 1995 .

[12]  Carsten Vogt,et al.  Ultrafine particles to save cement and improve concrete properties , 2005 .

[13]  Ivan Odler,et al.  6 – Hydration, Setting and Hardening of Portland Cement , 1998 .

[14]  François de Larrard,et al.  Ultrafine particles for the making of very high strength concretes , 1989 .

[15]  B. Lothenbach,et al.  The Role of Calcium Carbonate in Cement Hydration , 2007 .

[16]  Gilles Chanvillard,et al.  Determining the apparent activation energy of concrete Ea: numerical simulations of the heat of hydration of cement , 2002 .

[17]  J. J. Beaudoin,et al.  Effect of nano-CaCO3 on hydration of cement containing supplementary cementitious materials , 2011 .

[18]  Gaurav Sant,et al.  Hydration and strength development in ternary portland cement blends containing limestone and fly ash or metakaolin , 2013 .

[19]  Luc Taerwe,et al.  Influence of limestone powder used as filler in SCC on hydration and microstructure of cement pastes , 2007 .

[20]  T. L. Brownyard,et al.  Studies of the Physical Properties of Hardened Portland Cement Paste , 1946 .

[21]  J. Gaidis,et al.  A NEW MINERAL ADMIXTURE FOR HIGH-STRENGTH CONCRETE , 1989 .

[22]  P. F. Hansen,et al.  MATURITY COMPUTER FOR CONTROLLED CURING AND HARDENING OF CONCRETE , 1977 .

[23]  A. Katz,et al.  Effect of High Levels of Fines Content on Concrete Properties , 2006 .

[24]  Svante Arrhenius,et al.  Quantitative laws in biological chemistry , 2009 .

[25]  C. Poon,et al.  Hydration and properties of nano-TiO2 blended cement composites , 2012 .

[26]  B. Lagerblad,et al.  The function of fillers in concrete , 2004 .

[27]  W. A. Gutteridge,et al.  Filler cement: The effect of the secondary component on the hydration of Portland cement: Part I. A fine non-hydraulic filler , 1990 .

[28]  I. Soroka,et al.  Calcareous fillers and the compressive strength of portland cement , 1976 .

[29]  Erick Ringot,et al.  Mineral admixtures in mortars Effect of inert materials on short-term hydration , 2003 .