The measure of wettability of cement particles and the evaluation of the type and the strength of active surface sites of clinker particles were carried out to score the efficacy of organic grinding aids. The first analysis, based on the Washburn method, allows measuring the contact angle of cement with different solvents and is directly relatedf to the surface tension. The second analysis, based on the Hammet method, helps to classify the sites that may be responsible of the surface tension. Milled clinker (Portland clinker CEM I 52.5R; 0.025% w/wo DEG and TEA) was investigated. Firstly the wetting rates of powder with 4 different solvents (ethanol, n-hexane, toluene and formamide) were detected using a tensiometer. Then the powder dispersions in a solvent were titrated by acid solutions to get information on the acid/basic characterof the surface sites. Techniques and results are shown.
|Title of host publication||Eleventh International Conference on Superplasticizers and other Chemical Admixtures in Concrete|
|Subtitle of host publication||Ottawa, Ontario, Canada 10-13 July 2015|
|Editors||V. M. Malhotra, Pawan R. Gupta, Terence C. Holland|
|Place of Publication||Farmington Hills, MI|
|Number of pages||16|
|Publication status||Published - 31 Mar 2016|
|Event||11th International Conference on Superplasticizers and Other Chemical Admixtures in Concrete - Ottawa, Canada|
Duration: 10 Jul 2015 → 13 Jul 2015
|Conference||11th International Conference on Superplasticizers and Other Chemical Admixtures in Concrete|
|Period||10/07/15 → 13/07/15|
Paternò, V. A., Ottoboni, S., Goisis, M., & Gronchi, P. (2016). Evidences about the interactions between grinding aids and cement particles surface. In V. M. Malhotra, P. R. Gupta, & T. C. Holland (Eds.), Eleventh International Conference on Superplasticizers and other Chemical Admixtures in Concrete: Ottawa, Ontario, Canada 10-13 July 2015 (pp. 211-226). [SP-302-16] Farmington Hills, MI.