MATERIAL PROPERTIES OF MORTAR SPECIMENS AT EARLY STAGE OF HYDRATION IN THE PRESENCE OF POLYMERIC NANO-AGGREGATES
This work presents results on the influence of polymeric nano-aggregates on mortarmicrostructure and mechanical properties at very early hydration stage, starting 24h and until28 days of age. The polymeric nano-aggregates were core-shell micelles, produced fromPoly(ethylene oxide)-block-Polystyrene (PEO-b-PS) di-block copolymer (PEO113-b-PS218).The micelles were added to the mortar matrix as a solution (i.e. the mixing water was asolution of stabilized nano-aggregates in demi-water in concentration of 0.5 g/I). Themorphology and microstructure of the mortar matrix were investigated by ESEM. Imageanalysis was employed for calculating porosity and pore size distribution. The amourits ofhydration products and un-hydrated cement (in percent with hydration time) were calculated,using image segmentation by thresholding. The percent of hydrated water per dry cementweight was also determined wet chemically. Compressive strength was tested on intervals of24 h, 3, 7, 14, 28 and 56 days. For the period of 24h to 28 days, and compared to rest conditions, the mortar mixture,containing nano-aggregates exhibits: lower capillary porosity; higher compressive strength;contains similar to rest conditions amount of hydrated water and lower amount of un-hydratedcement. The nano-aggregates most likely act as nucleation sites for the formation of hydrationproducts, consequently have positive influence on the cementitious matrix. The result is adenser pore structure of the mortar matrix and enhanced mechanical properties.
D.A.Koleva Guang Ye Jian Zhou P.Petrov K.Van Breugel
Materials and Environment,Faculty of Civil Engineering and Geosciences,Delft University of Technolog Materials and Environment,Faculty of Civil Engineering and Geosciences,Delft University of Technolog Bulgarian Academy of Sciences,Institute of Polymers,Sofia,Bulgaria
国际会议
南京
英文
161-168
2008-10-13（万方平台首次上网日期，不代表论文的发表时间）