The study presented an analysis accessing the feasibility of using concrete containing marginal aggregates in concrete pavement slabs. The physical properties of aggregates were first determined and concrete was produ...The study presented an analysis accessing the feasibility of using concrete containing marginal aggregates in concrete pavement slabs. The physical properties of aggregates were first determined and concrete was produced from them. Marginal aggregates were found to have higher fines, absorption, soundness loss, micro-Deval abrasion loss, LA （Los Angeles） abrasion loss and lower specific gravity and unit weight when compared with standard aggregates. Workability of concrete containing marginal aggregate was found to be similar to concrete containing normal aggregates when Shilstone mix design method was used to optimize the concrete mixes. The compressive strength, splitting tensile, flexural strength and modulus of elasticity of concrete containing marginal aggregates were determined and found to be generally lower than concrete containing standard aggregates. A typical concrete pavement in Florida was modeled in FEACONSIV （finite element analysis of concrete slab） software developed at the University of Florida. Laboratory determined mechanical and thermal properties of concrete were inputted in FEACONS IV and analyzed for maximum induced stresses. Critical stress to strength ratios, i.e., ratio between maximum computed stresses obtained from FEACONS IV to modulus of rupture （strength） of concrete, was used as evaluation criterion for different concrete pavement mixes. It was found that, in general, concrete containing marginal aggregates have higher stress to strength ratios as compared with concrete containing standard aggregates.展开更多
In this article, we discuss a numerical method for the computation of the minimal and maximal solutions of a steady scalar Eikonal equation. This method relies on a penalty treatment of the nonlinearity, a biharmonic ...In this article, we discuss a numerical method for the computation of the minimal and maximal solutions of a steady scalar Eikonal equation. This method relies on a penalty treatment of the nonlinearity, a biharmonic regularization of the resulting variational problem, and the time discretization by operator-splitting of an initial value problem associated with the Euler-Lagrange equations of the regularized variational problem. A low-order finite element discretization is advocated since it is well-suited to the low regularity of the solutions. Numerical experiments show that the method sketched above can capture efficiently the extremal solutions of various two-dimensional test problems and that it has also the ability of handling easily domains with curved boundaries.展开更多
文摘The study presented an analysis accessing the feasibility of using concrete containing marginal aggregates in concrete pavement slabs. The physical properties of aggregates were first determined and concrete was produced from them. Marginal aggregates were found to have higher fines, absorption, soundness loss, micro-Deval abrasion loss, LA （Los Angeles） abrasion loss and lower specific gravity and unit weight when compared with standard aggregates. Workability of concrete containing marginal aggregate was found to be similar to concrete containing normal aggregates when Shilstone mix design method was used to optimize the concrete mixes. The compressive strength, splitting tensile, flexural strength and modulus of elasticity of concrete containing marginal aggregates were determined and found to be generally lower than concrete containing standard aggregates. A typical concrete pavement in Florida was modeled in FEACONSIV （finite element analysis of concrete slab） software developed at the University of Florida. Laboratory determined mechanical and thermal properties of concrete were inputted in FEACONS IV and analyzed for maximum induced stresses. Critical stress to strength ratios, i.e., ratio between maximum computed stresses obtained from FEACONS IV to modulus of rupture （strength） of concrete, was used as evaluation criterion for different concrete pavement mixes. It was found that, in general, concrete containing marginal aggregates have higher stress to strength ratios as compared with concrete containing standard aggregates.
基金supported by the National Science Foundation(No.DMS-0913982)
文摘In this article, we discuss a numerical method for the computation of the minimal and maximal solutions of a steady scalar Eikonal equation. This method relies on a penalty treatment of the nonlinearity, a biharmonic regularization of the resulting variational problem, and the time discretization by operator-splitting of an initial value problem associated with the Euler-Lagrange equations of the regularized variational problem. A low-order finite element discretization is advocated since it is well-suited to the low regularity of the solutions. Numerical experiments show that the method sketched above can capture efficiently the extremal solutions of various two-dimensional test problems and that it has also the ability of handling easily domains with curved boundaries.
