Studies on Lightweight High-Strength Shotcrete
With small deadweight, light-weight shotcrete can avoid the shotcrete lining from falling off, which benefits the bolt-shotcrete support of the roadway better under same bond strength. Light-weight shotcrete can be made by using clay ceramsite, polystyrene particles and fly-ash ceramsite to replace some gravel and sand. The experiments show that the characteristic of fly-ash ceramsite shotcrete is superior to that of clay shotcrete, while by replacing part of gravel and sand with polystyrene particles and fly-ash ceramsite, light-weight high strength shotcrete will have excellent combination properties.
Study on high performance lightweigh concrete with claypelletes
We use two types of clay pelletes as the aggregate and other common meterial seperately to compound high strengh,high performance lightweight concrete.Then we conduct the tests of physical properties,duriability and other performance on high strengh and high performance hightweight concrete that not pumped and pumped.The results show that this lightweight concrete have features of light self-quality,low coefficient of thermal conductivity and good performance of thermal isolation.Moreover,it has perfect physical performance,modulus of elasticity,grip of concrete,bonding strength and accord with the regular law about common concrete.In additon,its permeability and resistance to freezing and thawing is better than common concrete.
General expression for the density effect for the ionization loss of charged particles
The equations for the density-effect correction $\ensuremath{\delta}(X)$ for the ionization loss as given in a previous paper have been extended to the case where $\ensuremath{\delta}({X}_{0})\ensuremath{\equiv}{\ensuremath{\delta}}_{0}g0$. Here ${X}_{0}$ is the lower limit of the range ${X}_{0}lXl{X}_{1}$, where a particularly simple expression for $\ensuremath{\delta}(X)$ applies; $X={log}_{10}(\frac{p}{{m}_{0}c})$, where $p$ is the momentum and ${m}_{0}$ is the mass of the incident particle. The case ${\ensuremath{\delta}}_{0}g0$ applies directly to the calculation of $\ensuremath{\delta}(X)$ for conductors (metals).