Characterization of effects of thermal property of aggregate on the carbon footprint of asphalt industries in China

In this study, the effects of the thermal properties of asphalt binders and aggregate ma- terials were characterized in terms of the specific heat capacity （C） for energy consumption and environmental footprints of hot mix asphalt （HMA） and warm mix asphalt （WMA）. Asphalt mixes produced using low-C aggregate are found to be more energy-efficient and environmental friendly, irrespective of the binder type and construction technology. Therefore, different fractions of aggregate blends were replaced with the aggregate pro- vided from a ]ow-C source or sustainable source. Analysis of energy consumption clearly indicated that the specific energy and environmental footprints decrease linearly as the low-C aggregate content increases. The amount of energy saving realized in the asphalt industries by the use of low-C aggregate is significant on a national scale in China. In this regard, China was chosen as a case study. Analysis of fuel requirement clearly indicated that the production of WMA using high thermal sensitivity aggregate can yield significant energy saving sufficient to fuel 44,007 to 664,880 Chinese households per year. Therefore, use of low C aggregate in asphalt mix production can be adopted as a strategy to produce WMA and HMA.

化学结构对聚羧酸基超塑化剂的空间稳定性的影响

为了阐明含有聚氧乙烯接枝侧链的聚羧酸系超塑化剂的流动机理,文章研究了接枝共聚物的化学结构对水泥分散性能的影响。有长接枝链的共聚物表现为较好的分散能力和低的吸附量。吸附量研究表明随着吸附密度的增加接枝链被拉长。吸附在水泥颗粒表面的共聚物接枝链的厚度取决于两个接枝共聚物间的平均距离和共聚物内部接枝链的间距,还取决于共聚物的几何学特征。改进的空间稳定性模型合并了由于吸附导致接枝链的拉长和共聚物的几何学约束,给出了含有不同种接枝共聚物水泥浆吸附和流动关系的有用的解释。