Complex Evaluation of the Mechanical and Fracture Properties of Cementitious Materials with Different Water-Cement Ratio

Complex Evaluation of the Mechanical and Fracture Properties of Cementitious Materials with Different Water-Cement Ratio

Stať ve sborníku mimo WoS a Scopus

This paper is aimed at the development of the physical, mechanical and fracture characteristics of cementitious materials during ageing. Three mortars which differed only in the water-cement ratio (w/c) were prepared for manufacturing of the test specimens intended for the experiments. All mortars were prepared using the standardized quartzite sand with the particle grain size distribution of 0−2 mm CEN 196-1, CEM I 42.5 R Portland cement (cement plant Mokrá, Czech Republic) and water. The reference w/c was set to the value of 0.5. To produce two other mortars, this ratio was reduced by approx. 5 and 30 %. This resulted in w/c ratio 0.47 and 0.35 respectively. All test specimens were not protected intentionally from drying during the whole time of measurement and were stored in laboratory at ambient temperature of 21 ± 2 °C and relative humidity of 60 ± 10 %. The results of the shrinkage, elastic, fracture and strength parameters determined within the time interval from 3 days to 2 years of ageing are summarized and discussed in the paper. The results of performed experiments were partially published within the conference DYN-WIND’17. This paper focuses especially on the evaluation of the results obtained after 2 years of specimens ageing and also provides a complex discussion of the results gathered during the whole time of ageing. The results show a crucial impact of the w/c on the final values of mechanical and fracture characteristics.

This paper is aimed at the development of the physical, mechanical and fracture characteristics of cementitious materials during ageing. Three mortars which differed only in the water-cement ratio (w/c) were prepared for manufacturing of the test specimens intended for the experiments. All mortars were prepared using the standardized quartzite sand with the particle grain size distribution of 0−2 mm CEN 196-1, CEM I 42.5 R Portland cement (cement plant Mokrá, Czech Republic) and water. The reference w/c was set to the value of 0.5. To produce two other mortars, this ratio was reduced by approx. 5 and 30 %. This resulted in w/c ratio 0.47 and 0.35 respectively. All test specimens were not protected intentionally from drying during the whole time of measurement and were stored in laboratory at ambient temperature of 21 ± 2 °C and relative humidity of 60 ± 10 %. The results of the shrinkage, elastic, fracture and strength parameters determined within the time interval from 3 days to 2 years of ageing are summarized and discussed in the paper. The results of performed experiments were partially published within the conference DYN-WIND’17. This paper focuses especially on the evaluation of the results obtained after 2 years of specimens ageing and also provides a complex discussion of the results gathered during the whole time of ageing. The results show a crucial impact of the w/c on the final values of mechanical and fracture characteristics.

Cement; shrinkage; modulus of elasticity; fracture test; fracture toughness.

Cement; shrinkage; modulus of elasticity; fracture test; fracture toughness.

KUCHARCZYKOVÁ, B.; ŠIMONOVÁ, H.; KOCÁB, D.; HODULÁKOVÁ, M.

2020

24.06.2019

IA-FraMCoS

France

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