High volume Pozzolan concrete: three years of industrial experience in Texas with CemPozz
2009 (English)In: Concrete in Focus, Vol. 8, no 2, 22-27 p.Article in journal (Other academic) Published
High Volume Pozzolan Concrete (HVPC) can be manufactured with low carbon dioxide footprint and energy consumption with the help of a new technology based on Energetically Modified Cement (EMC). The technology consists of mechanical processing a blend of ordinary portland cement (PC) and a pozzolan (Class F fly ash) through multiple high intensity grinding mills. The process imparts an increased surface activation of the PC and the pozzolan particles. Fly ash may be processed with all cements forming ready-to-use cement. Alternatively, fly ash can be processed with a small amount of cement (circa 5% by weight) and used as a pozzolan added to the concrete mixer. The latter product is called CemPozz and has been produced from 2004 by Texas EMC Products, Ltd, at the Limestone plant in Jewett, Texas. It can replace up to 60% of the PC in concrete. The performance of CemPozz (mechanically processed pozzolan) in concrete is equivalent to Grade 100 blast furnace slag in accordance with ASTM C 989 "Standard Specification for Ground Granulated Blast-Furnace Slag for Use in Concrete and Mortars."Th e strength of HVPC with 50% CemPozz is comparable to concrete made of ordinary portland cement, the setting time is similar, with improvements to alkali-silica reactivity mitigation and drying shrinkage. Concretes produced with CemPozz also have much higher sulfate resistance, very low permeability to chloride ions and are characterized by a signifi cantly reduced cracking.Th ere are three environmental benefi ts with the EMC-based HVPC: (i) You can activate a fl y ash that otherwise would not be suitable for high replacement of PC in concrete, (ii) You can reduce the CO 2 footprint by using a much less amount of clinker as concrete binder, and (iii) You can reduce the energy consumption associated with the binder. Calculations show that as much as 45% can be saved in energy with 45% less CO2 emissions when 50% fl y ash of cement mass is used with the EMC technology. During the period 2004-2007, over two million cubic yards (1.5 million cubic meters) of High Volume Pozzolan Concrete (HVPC) made with CemPozz have been manufactured in Texas and eff ectively used for different applications in Texas (highway paving, housing concrete, shotcrete and blocks). TX DOT and PENNDOT have included CemPozz in their specifications, which allow 50% replacement of portland cement by weight. Udgivelsesdato: March/April
Place, publisher, year, edition, pages
2009. Vol. 8, no 2, 22-27 p.
Research subject Structural Engineering
IdentifiersURN: urn:nbn:se:ltu:diva-12476Local ID: ba1ab940-fa89-11dd-9fef-000ea68e967bOAI: oai:DiVA.org:ltu-12476DiVA: diva2:985427
Godkänd; 2009; Bibliografisk uppgift: NRC-S0109/8215; 20090214 (elfgren)2016-09-292016-09-29Bibliographically approved