3.1.1. Physical properties test

The routine performance of the three asphalts were tested in accordance with the specification, respectively. The results are summarized in Table  3.

Table 4 shows that addition of TM-P in asphalt shows increase in softening point while decrease in penetration value. The soften- ing point of TM-P modified phosphorus slag powder asphalt    was

increased  by  1.7 °C  and  the  penetration  rate  was  decreased  by 0.31 mm compared with the virgin asphalt, and the unmodified phosphorus slag powder asphalt 0.9 °C and 0.26 mm. It shows  that the addition of TM-P modified phosphorus slag powder has a favourable effect on the viscosity and high temperature properties of virgin asphalt.

2.3.2. Mineral grade  design

3.1.2. Dynamic Shear Rheometer (DSR) test

Based on the idea of rheology, extensive experimental researches were carried out on the high and low temperature per- formance of the asphalt binder and SHRP proposed the new rheo- logical performance test method of the asphalt binder [18]. According to the SHRP asphalt  test  specification  requirements, the rheological properties of the asphalt binder were measured using DSR on three kinds of specimens namely initial asphalt spec-According to the results of aggregate screening, AC-16 asphalt mixture grada- tion designing by Marshall method was selected in this paper. The synthetic grada- tion is shown in Fig. 5.

2.3.3. Determination of the optimum asphalt content

According to the ‘‘Asphalt & Asphalt Mixture Test Code” (JTG E20-2011) and combining with engineering actual situation, five modified and unmodified asphalt content (3.9%, 4.3%, 4.7%, 5.1%, 5.5%) were carried out respectively to determine the optimum asphalt content  with  the  same  standard  Marshall  test  conditions (150 ± 5 °C, double-sided compaction of 75 times). Based on the physical and mechanical indexes of the specimen, it is recommended that the optimum asphalt aggregate ratio for virgin asphalt mixture is 4.6% and 4.7% for the slag powder mod- ified asphalt one. The specific results are shown in Tables 1 and  2.

3. Test methods and analysis

3.1. Asphalt performance tests

The slag powder modified by TM-P was added into the virgin asphalt mixing with colloid mill to prepare the slag powder mod-imen, short-term aged specimen and long-term aged  specimen. The results are shown in Figs.   6–8.

(M-TM-P means modified phosphate type single alkyl oxygen base titanates and U-TM-P means unmodified phosphate type sin- gle alkyl oxygen base  titanates)

The experimental analysis shows that:

摘要：本文采用磷酸盐类单烷基氧基钛酸酯TM-P对磷渣粉表面进行改性。采用扫描电子显微镜（SEM）对磷渣颗粒的表面特性和改性机理进行了表征。 通过傅里叶变换红外光谱（FTIR），动态剪切流变试验（DSR），马歇尔试验，车辙试验和冻融 - 解冻试验，分析了表面改性磷矿渣粉对沥青和沥青混合料的影响和机理。 结果表明，TM-P改性磷矿粉（粉末重量的10％）提高了与沥青的相容性，使沥青混合料的抗老化性，抗车辙性和抗水损害性增加。

1、介绍

中国的磷酸盐资源丰富，在世界上的总存储量仅次于摩洛哥[1]。据统计，