Abstract: The present disclosure provides a retroreflective glass bead that includes at least one high refractive oxide selected from the group consisting of TiO2, BaO, La2O and Bi2O3; and at least one additive selected from the group consisting of MgO, CaO, ZnO, ZrO2, Al2O3, K2O, Na2O, Li2O and SrO. The glass bead according to the present invention have excellent retroreflectivity according to optical properties and excellent durability and productivity due to a simple structure, and also can be produced in various colors due to high chemical stability. Thus, the retroreflective aggregate including the glass bead according to the present invention exhibits very high visibility under various circumstances such as rainy or dry conditions. In addition, the method of producing a glass bead according to the present invention can reduce manufacturing costs while ensuring excellent productivity.

Abstract: The present disclosure provides a retroreflective glass bead that includes at least one high refractive oxide selected from the group consisting of TiO2, BaO, La2O and Bi2O3; and at least one additive selected from the group consisting of MgO, CaO, ZnO, ZrO2, Al2O3, K2O, Na2O, Li2O and SrO. The glass bead according to the present invention have excellent retroreflectivity according to optical properties and excellent durability and productivity due to a simple structure, and also can be produced in various colors due to high chemical stability. Thus, the retroreflective aggregate including the glass bead according to the present invention exhibits very high visibility under various circumstances such as rainy or dry conditions. In addition, the method of producing a glass bead according to the present invention can reduce manufacturing costs while ensuring excellent productivity.

Abstract: The present invention relates to a pigment dispersion and a black water-reducing agent, more particularly, to a pigment dispersion comprising a carbon black whose surface is modified with an aminosilane compound and a polycarboxylic acid-based water-reducing agent, and a black water-reducing agent using the same. The present invention is characterized in that the surface-modified carbon black with an aminosilane compound is water-dispersed by using a polycarboxylic acid-based water-reducing agent as a dispersing agent having better performance than a naphthanlene-based water-reducing agent. Therefore, the present invention can display black color of the water-reducing agent and cement at the same time and improve the flowability of cement owing to the presence of carbon black in the form of nanoparticles, which enables to manufacture ultrahigh strength concrete.