The method,in which a few carats of diamond grits are placed inside a capsule together with a steel ball,shaken for a number of times,and the unbroken ratio of the grits is then used to evaluate the quality of the dia...The method,in which a few carats of diamond grits are placed inside a capsule together with a steel ball,shaken for a number of times,and the unbroken ratio of the grits is then used to evaluate the quality of the diamond,has been well established for many years.However,the unbroken percentage,in an equivalent view,represents the impact toughness of the grits and cannot reflect the value of the crushing energy.Most of the previous empirical formulas obtained from experiments by scholars cannot be applied to practical tests.In this paper,a dimensional analysis was applied to investigate the impact toughness experiment,and the dimensionless relationship has been built among those variables such as the toughness index,the impact time,the impact frequency and the crushing energy per unit area.According to the results of a large number of experiments with synthetic diamond grits of mesh size 45/50,the percentage of the broken grits H is proportional to the impact time T^（1.14） when the impact frequency is 2400 r/min,and the impact frequency f^（2.576） when the number of impacts is 2000.展开更多
This paper presents the evaluation of the potential aggregate source for pavement construction in Pakistan. Recently the demand for construction materials has been increased significantly due to the establishment of t...This paper presents the evaluation of the potential aggregate source for pavement construction in Pakistan. Recently the demand for construction materials has been increased significantly due to the establishment of the China-Pakistan Economic Corridor (CPEC) Projects. Therefore, it is essential to look for new resources of construction materials along with the CPEC routes in consideration of this increasing demand. In this context, a Physical and Mechanical characterization investigation is carried out on the Permian Wargal Limestone from Zaluch Nala, Salt Range to explore their potential to utilize as construction materials. The studied samples have tolerable values for all standard engineering parameters, proposed by various national and international agencies such as AASHTO, ASTM, BS, and NHA. Furthermore, as a performance indicator of aggregate overall quality, the evaluated mechanical qualities were integrated into a single characteristic, Toughness Index (TI). The TI values also suggested that the Permian Wargal limestone aggregates meet international quality standards for pavement construction. On the basis of geotechnical testing and Toughness Index (TI), the late Permian Wargal limestone, Zaluch Nala, Salt Range, is strongly recommended as a potential aggregate resource for mega projects such as the China-Pakistan Economic Corridor (CPEC) and other construction projects.展开更多
基金Supported by the National Natural Science Foundation of China(11572047)
文摘The method,in which a few carats of diamond grits are placed inside a capsule together with a steel ball,shaken for a number of times,and the unbroken ratio of the grits is then used to evaluate the quality of the diamond,has been well established for many years.However,the unbroken percentage,in an equivalent view,represents the impact toughness of the grits and cannot reflect the value of the crushing energy.Most of the previous empirical formulas obtained from experiments by scholars cannot be applied to practical tests.In this paper,a dimensional analysis was applied to investigate the impact toughness experiment,and the dimensionless relationship has been built among those variables such as the toughness index,the impact time,the impact frequency and the crushing energy per unit area.According to the results of a large number of experiments with synthetic diamond grits of mesh size 45/50,the percentage of the broken grits H is proportional to the impact time T^（1.14） when the impact frequency is 2400 r/min,and the impact frequency f^（2.576） when the number of impacts is 2000.
文摘This paper presents the evaluation of the potential aggregate source for pavement construction in Pakistan. Recently the demand for construction materials has been increased significantly due to the establishment of the China-Pakistan Economic Corridor (CPEC) Projects. Therefore, it is essential to look for new resources of construction materials along with the CPEC routes in consideration of this increasing demand. In this context, a Physical and Mechanical characterization investigation is carried out on the Permian Wargal Limestone from Zaluch Nala, Salt Range to explore their potential to utilize as construction materials. The studied samples have tolerable values for all standard engineering parameters, proposed by various national and international agencies such as AASHTO, ASTM, BS, and NHA. Furthermore, as a performance indicator of aggregate overall quality, the evaluated mechanical qualities were integrated into a single characteristic, Toughness Index (TI). The TI values also suggested that the Permian Wargal limestone aggregates meet international quality standards for pavement construction. On the basis of geotechnical testing and Toughness Index (TI), the late Permian Wargal limestone, Zaluch Nala, Salt Range, is strongly recommended as a potential aggregate resource for mega projects such as the China-Pakistan Economic Corridor (CPEC) and other construction projects.
