In order to further speed up the construction progress,shorten the rolling time and reduce the rolling times of roller compacted concrete after analyzing work of construction progress improvement measures of roller co...In order to further speed up the construction progress,shorten the rolling time and reduce the rolling times of roller compacted concrete after analyzing work of construction progress improvement measures of roller compacted concrete,research on vibration sensitive admixture is carried out and satisfactory results are acquired.The new type vibration sensitive admixture was used in the project of Jinghong hydropower station in Yunnan Province,China.The engineering experimental results show that various indexes have been verified.Meanwhile,the compactness of roller compacted concrete is improved under the same rolling times,the rolling times and the duration time can be reduced under the same compactness requirement in construction practice.展开更多
Vacuum insulation panels provide unprecedented possibilities for renovating the existing building stock in a manner that reduces the thermal losses through the building envelope. This study is focused on the implement...Vacuum insulation panels provide unprecedented possibilities for renovating the existing building stock in a manner that reduces the thermal losses through the building envelope. This study is focused on the implementation of VIPs （vacuum insulation panels） in energy retrofit projects with rendered outer walls. Particular emphasis is put on reducing the thermal bridges due to mechanical fasteners and at the joints of the panels. These are evaluated through a parametric study of the impact of the thermal conductivity of the joints of the panels and the adjacent insulation layer as well as the material of the fasteners. The study is carried out with 3D FEM （finite element method） simulations software. Furthermore, the moisture conditions in the construction are studied. The dynamic moisture behavior of a wall construction is modeled with a two dimensional FEM model. The long term effects of vapor diffusion are investigated in terms of accumulated moisture and the risk of condensation. The results illustrate that vacuum insulation on the outside of the wall construction does not pose a moisture problem to the construction. The simulations are based on a draft of a new technical solution for the refurbishment of a building that is typical for the great Swedish building program of the 1970s.展开更多
文摘In order to further speed up the construction progress,shorten the rolling time and reduce the rolling times of roller compacted concrete after analyzing work of construction progress improvement measures of roller compacted concrete,research on vibration sensitive admixture is carried out and satisfactory results are acquired.The new type vibration sensitive admixture was used in the project of Jinghong hydropower station in Yunnan Province,China.The engineering experimental results show that various indexes have been verified.Meanwhile,the compactness of roller compacted concrete is improved under the same rolling times,the rolling times and the duration time can be reduced under the same compactness requirement in construction practice.
文摘Vacuum insulation panels provide unprecedented possibilities for renovating the existing building stock in a manner that reduces the thermal losses through the building envelope. This study is focused on the implementation of VIPs （vacuum insulation panels） in energy retrofit projects with rendered outer walls. Particular emphasis is put on reducing the thermal bridges due to mechanical fasteners and at the joints of the panels. These are evaluated through a parametric study of the impact of the thermal conductivity of the joints of the panels and the adjacent insulation layer as well as the material of the fasteners. The study is carried out with 3D FEM （finite element method） simulations software. Furthermore, the moisture conditions in the construction are studied. The dynamic moisture behavior of a wall construction is modeled with a two dimensional FEM model. The long term effects of vapor diffusion are investigated in terms of accumulated moisture and the risk of condensation. The results illustrate that vacuum insulation on the outside of the wall construction does not pose a moisture problem to the construction. The simulations are based on a draft of a new technical solution for the refurbishment of a building that is typical for the great Swedish building program of the 1970s.
