No abstract

Taking modified unsaturated polyester as the matrix resin, methyl ethyl ketone peroxide (MEKPO) and cobalt naphthenate as the redox system, and TiO2, SiO2 and hollow glass beads as the functional fillers, a thermosetting heat-reflective coating with good temperature-reduction effects and wearing resistance, which can be quickly solidified under the room temperature has been produced. In accordance to the research, the amount of solidifying agent and accelerant has great bearing on the gelation time of the coating, and the optimum usage for this system of which will be: 2.5% cobalt naphthenate and 2% MEKPO or 3% cobalt naphthenate and 2% MEKPO; as the increase of the fillers, the temperature reduction effects will be quickly enhanced at the beginning, and then tend to be stable, when the quantity of the fillers is less than 10%, the covering effect of the coating is not obvious, when it is more than 20%, construction difficulties will occur because of the excessive viscosity of the coating. Fillers of 14% with low viscosity and better temperature reduction effect is recommended; as the ratio of TiO2 to SiO2 decreases, the temperature reduction effect of the coating is weakened while the abrasion resistance strengthened and the glossiness reduced; the addition of hollow glass bead can better realize the temperature reduction of the coating, however the glossiness of which will be increased; Colored pigments have slightly negative impact on the temperature reduction of coating. The prepared coating has good abrasion resistance, and can reduce the pavement temperature by almost 10 during hot seasons when it is applied on pavement.

No abstract

Base asphalt can be separated into four fractions, which are saturates, naphetene aromatics, polar-aromatics and asphaltenes. The thermal oxidation process of each fraction was studied by in-situ Fourier transform infrared (FTIR) analysis in different atmospheres in this paper. And the results show that each fraction in nitrogen atmosphere has no obvious aging phenomenon, while in oxygen and air atmosphere, only saturates and naphetene aromatics have a drastic change because of thermal oxidation, and polar-aromatics and asphaltenes almost keep unchanged. When adding 2.5% antioxidant 300 or 5% SBS respectively to saturates and naphthene aromatics, it can be found from the results that the degree of thermal oxidation of these two components decrease.

The addition of fiber into concrete can not only suppress the interior shrinkage strain and decrease the thermal dilation coefficient (TDC) of concrete, but also it can lessen the width of shrinkage crack, especially reduce the appearance of interconnected pore, thus the reduction of the water content of capillary pore will make the TDC of paste matrix lessen. In this paper, an experiment was designed to study the TDC from the 5th day to the 29th day after the concrete was poured. The results show that the addition of fiber can effectively reduce the TDC of concrete. When the addition is the same, high-modulus carbon fiber reinforced concrete has a lower TDC than low-modulus polyester fiber concrete.