Abstract:
Elements produced with dry consistency concrete are widely used in the country, such as in concrete pipes. Shrinkage compensating admixtures are commonly employed in the construction of concrete slabs for floors. These products, based on supercalcined calcium oxide, present volumetric expansion that compensates shrinkage, minimizing possible risks of cracking. In addition, it may fill the pores of the matrix and decrease its porosity and permeability, increasing its mechanical strength and service life. In this context, the objective of this study was to evaluate the use of shrinkage compensating admixtures in dry consistency concretes. The properties of the admixture were analyzed by X-ray diffraction and laser diffractometry. The experimental program consisted in analyzing hydration kinetics of cement pastes by isothermal calorimetry, volumetric stability in mortars and mechanical strength in dry consistency concretes. Results showed that the admixture accelerates hydration rates and increase the hydration degree of cement pastes at early ages. Moreover, it compensated the shrinkage of the matrix, leading to increases in mechanical strength.
Reference:
2. OLIVEIRA, Caroline U.; POLIZEL, Matheus M.; SILVA, Claudio O. Silva; QUARCIONI, Valdecir Angelo; SALVADOR, Renan P. Aplicação de aditivos compensadores de retração em concretos de consistência seca. In: CONGRESSO BRASILEIRO DO CONCRETO, 62., 2021, Florianópolis. Anais…
Access to articles, with password, on the event website:
http://ibracon.org.br/eventos/62cbc/artigos/
Elements produced with dry consistency concrete are widely used in the country, such as in concrete pipes. Shrinkage compensating admixtures are commonly employed in the construction of concrete slabs for floors. These products, based on supercalcined calcium oxide, present volumetric expansion that compensates shrinkage, minimizing possible risks of cracking. In addition, it may fill the pores of the matrix and decrease its porosity and permeability, increasing its mechanical strength and service life. In this context, the objective of this study was to evaluate the use of shrinkage compensating admixtures in dry consistency concretes. The properties of the admixture were analyzed by X-ray diffraction and laser diffractometry. The experimental program consisted in analyzing hydration kinetics of cement pastes by isothermal calorimetry, volumetric stability in mortars and mechanical strength in dry consistency concretes. Results showed that the admixture accelerates hydration rates and increase the hydration degree of cement pastes at early ages. Moreover, it compensated the shrinkage of the matrix, leading to increases in mechanical strength.
Reference:
2. OLIVEIRA, Caroline U.; POLIZEL, Matheus M.; SILVA, Claudio O. Silva; QUARCIONI, Valdecir Angelo; SALVADOR, Renan P. Aplicação de aditivos compensadores de retração em concretos de consistência seca. In: CONGRESSO BRASILEIRO DO CONCRETO, 62., 2021, Florianópolis. Anais…
Access to articles, with password, on the event website:
http://ibracon.org.br/eventos/62cbc/artigos/
