Thermochemical pretreatments for agricultural residue ash production for concrete

Agricultural residue ash is known to be a very reactive source of supplementary cementitious material (SCM) for use in concrete. The influence of thermochemical pretreatments on the reactivity of agricultural residue ash (ARA) was studied for its use as an SCM. It was shown that pretreatments are effective in the partial removal of alkali metals and other impurities out of both wheat straw and rice straw, leading to ARA with lower loss on ignition (LOI), higher internal surface area, and higher amorphous silica content than unpretreated ARA. It was shown that the alkali content correlated with the LOI and amorphous silica content of the ash. When used at a cement replacement rate of 20% by mass, pretreated ARA accelerated the hydration of cement paste samples, whereas unpretreated ARA retarded the cement hydration. Pretreatments were found to increase ARA reactivity, as measured by calcium hydroxide content reduction with time. ARA increased the compressive strength of mortar samples by 25% when used as 20% replacement of cement in the samples. The calcium hydroxide content of paste samples and mortar compressive strength was found to correlate to the amorphous silica content of the ash.

[1]  C. Wyman,et al.  Features of promising technologies for pretreatment of lignocellulosic biomass. , 2005, Bioresource technology.

[2]  Guang Ye,et al.  Hydration and microstructure of ultra high performance concrete incorporating rice husk ash , 2011 .

[3]  Ruihong Zhang,et al.  Overview of biomass pretreatment for cellulosic ethanol production. , 2009 .

[4]  Mohammad Shafiur Rahman.  Dehydration and Microstructure , 2008 .

[5]  A. E. Damatty,et al.  An Economical Solution for the Environmental Problem Resulting from the Disposal of Rice Straw , 2009 .

[6]  B. Saha,et al.  Dilute acid pretreatment, enzymatic saccharification and fermentation of wheat straw to ethanol , 2005 .

[7]  A. Nonat,et al.  Hydration of cementitious materials, present and future , 2011 .

[8]  G. C. Cordeiro,et al.  Use of ultrafine rice husk ash with high-carbon content as pozzolan in high performance concrete , 2009 .

[9]  M. Himmel,et al.  Welcome to Biotechnology for Biofuels , 2008, Biotechnology for biofuels.

[10]  S. Wansom,et al.  Characterizing pozzolanic activity of rice husk ash by impedance spectroscopy , 2010 .

[11]  David A Lange,et al.  Comparison of two processes for treating rice husk ash for use in high performance concrete , 2009 .

[12]  P. Nimityongskul,et al.  Effects of temperature and alkaline solution on electrical conductivity measurements of pozzolanic activity , 2011 .

[13]  L. Vlaev,et al.  Utilization of Rice Husks and the Products of Its Thermal Degradation as Fillers in Polymer Composites , 2011 .

[14]  Bryan M. Jenkins,et al.  Biomass leachate treatment by reverse osmosis , 2003 .

[15]  Byron Burlingame,et al.  ASTM F1518—00 Standard Practice for Cleaning and Disinfection of Flexible Fiberoptic and Video Endo scopes Used in the Examination of the Hollow Viscera. West Conshohocken, PA: ASTM International; 2000:663. , 2009 .

[16]  A.L.A. Fraaij,et al.  Reactive pozzolanas from rice husk ash: An alternative to cement for rural housing , 2006 .

[17]  Claus Felby,et al.  Cell-wall structural changes in wheat straw pretreated for bioethanol production , 2008, Biotechnology for biofuels.

[18]  Almir Sales,et al.  Use of Brazilian sugarcane bagasse ash in concrete as sand replacement. , 2010, Waste management.

[19]  S. Chandrasekhar,et al.  Effect of calcination temperature and heating rate on the optical properties and reactivity of rice husk ash , 2006 .

[20]  Kyle A. Riding,et al.  Early age strength enhancement of blended cement systems by CaCl2 and diethanol-isopropanolamine , 2010 .

[21]  N. Al-Akhras,et al.  Effect of wheat straw ash on mechanical properties of autoclaved mortar , 2002 .

[22]  Jordi Payá,et al.  Enhanced conductivity measurement techniques for evaluation of fly ash pozzolanic activity , 2001 .

[23]  Fevziye Aköz,et al.  Study of pozzolanic properties of wheat straw ash , 1999 .

[24]  Sheetal K. Agarwal,et al.  Pozzolanic activity of various siliceous materials , 2006 .

[25]  Pichai Nimityongskul,et al.  Quick monitoring of pozzolanic reactivity of waste ashes. , 2009, Waste management.

[26]  J. Bullard,et al.  Mechanisms of cement hydration , 2011 .

[27]  S. Kothandaraman,et al.  Optimum production conditions for reactive rice husk ash , 2010 .

[28]  Qingge Feng,et al.  Study on the pozzolanic properties of rice husk ash by hydrochloric acid pretreatment , 2004 .