Design and characterization of low-heat and low-alkalinity cements

Journal Article · Tue Apr 15 00:00:00 EDT 2008 · Cement and Concrete Research

DOI:https://doi.org/10.1016/j.cemconres.2007.12.002· OSTI ID:21033072

Codina, M ^[1]; Le Bescop, P ^[2]; Verdier, J; Ollivier, J P ^[3]

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1. ANDRA, Direction Scientifique, Service Colis/Materiaux, Parc de la Croix Blanche, 1-7 rue Jean Monnet, 92298 Chatenay-Malabry cedex (France)
2. Commissariat a l'Energie Atomique, DPC/SCCME/LECBA, CEN Saclay, 91191 Gif-sur-Yvette (France)
3. Laboratoire Materiaux et Durabilite des Constructions, INSA Toulouse, 135 avenue de Rangueil, 31077 Toulouse cedex 4 (France)

Investigations were carried out to formulate and characterize low-alkalinity and low-heat cements which would be compatible with an underground waste repository environment. Several systems comprising Portland cement, a pozzolan (silica fume or fly ash) and blastfurnace slag were compared. All blends were characterized by high amounts of additions, the Portland cement (PC) fraction ranging only from 20 to 60%. Cement hydration was studied using several techniques: X-ray Diffraction, TGA-DTA, calorimetry, pore solution extraction and microscopy. The most important result obtained with some ternary blends was the drop in the pore solution pH by more than one unit as compared with control samples elaborated with commercial cements. The alkali content ({approx} 1 to 4 mmol/L) of the interstitial solution was also strongly reduced. The blends exhibited a low-heat output as required. Leaching tests carried out in pure water indicated a very slow decalcification of the samples. Several techniques such as optical microscopy, SEM/BSE, X-ray microanalysis or X-ray diffraction were compared to estimate the degraded thickness.

• OSTI ID: 21033072
• Journal Information: Cement and Concrete Research, Vol. 38, Issue 4; Other Information: DOI: 10.1016/j.cemconres.2007.12.002; PII: S0008-8846(07)00309-2; Copyright (c) 2007 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0008-8846
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ACID NEUTRALIZING CAPACITY
CALORIMETRY
DESIGN
DIFFERENTIAL THERMAL ANALYSIS
EXTRACTION
FLY ASH
HEAT
HYDRATION
INTERSTITIALS
LEACHING
MICROANALYSIS
OPTICAL MICROSCOPY
PORTLAND CEMENT
SCANNING ELECTRON MICROSCOPY
SILICA
THERMAL GRAVIMETRIC ANALYSIS
WASTE MANAGEMENT
X-RAY DIFFRACTION