This investigation means to predict and modeling the fresh and hardened concrete behavior containing fine aggregates from concrete and brick wastes, for different recycled aggregates substitution rates. To succeed this, the design of experiments DOE method was used. It is observed that slump of recycled concrete is significantly influenced by the content in recycled concrete aggregates (RCA), natural sand (NS) and recycled brick aggregates (RBA), respectively.The compressive strength (CS) reaches a maximum value of 83.48 MPa with factors values of 25% RBA, and 75% RCA. And HPC’s based on RBA sand presented greater values of flexural strength at 7 days than HPC’s based on RCA sand, it was revealed that this is due to the RBA fines pozzolanic reaction and the production of new CSHs, which leads to better cement matrix densification.Under optimal conditions, themaximum desirability is 0.65, who has given HPC no added natural sand, by mixing recycled sands RBA (9.5%) with RCA (90.5%).The statistical terms result show that the expected models are very well correlated with the experimental data and have shown good accuracy.

Earth dams remain the most used means of water mobilization in Algeria, due to their lower cost compared to concrete gravity dams and their capacity to resist better to seismic excitations. A study of the hydraulic structure was carried out in this paper, according to simple rules and empirical approaches. During the last decade, several high earth dams have suffered significant failures of the upstream or downstream slopes at the end of construction, after the initial impoundment, and under seismic loads. To prevent this occurrence or to minimize the damage in these hydraulic structures, a reexamination of the earth dams' behavior using more elaborate calculation methods is necessary. The purpose of the current study is to numerically model the behavior and analyze the stability of earth dams in terms of displacements at the end of construction, after the initial impoundment, during an earthquake, and compare these displacements with those measured in situ. A case study was conducted for the Taksebt - Tizi Ouzou dam by using the Plaxis 2D calculation code and the finite element method. The comparison of the obtained results shows a close concordance with the monitoring results of the dam carried out by various specialized organizations.

In this research, the different methods to calculate the earth pressures on a retaining wall were exposed, for different loading conditions, namely static and dynamic. The dynamic response of a retaining wall under seismic loading was also studied. The simulation is done using the finite element code PLAXIS. The response is expressed in terms of acceleration and displacement. When using numerical models to study this type of problem, two different entities can be identified. The first one corresponds to the materials and the consideration of their behavior. The second part corresponds to the type of loading imposed, i.e. the input signal.

With the increase of solid construction waste (CSW) due to the acceleration of urbanization in Algeria, many ecological and environmental issues have been raised. Recycling and reuse of construction waste helps to reduce pollution, carbon emissions and preserve resources. Few studies have focused on the durability characteristics of concretes based on fine aggregates recycled from brick and concrete waste. The main purpose of this study is to formulate and analyze the performance of HPC based on waste brick and concrete fines. The substitution of alluvial sand with brick fines, causes the reduction of the heat of hydration and delays the appearance of the thermal flux peaks. while HPC rich in crushed concrete waste increases the heat of hydration. The appearance of heat flux peaks coincides for all mixtures with fines of waste concrete substitution and they will be delayed and prolonged for HPC with sand based on waste brick.

This study aims primarily to perform a comparative analysis of the seismic response of a soil profile, in the time and frequency domains, in order to evaluate the seismic response of soil subjected to seismic excitation. After a few remarks made on the responses given by the linear elasticity method for this type of problem, it was considered necessary to use SHAKE 2000 and PLAXIS in this study. The obtained results were then compared with those of the available theoretical predictions. Rock elasticity, viscous damping and damping by hysteresis, and the nonlinearity of the ground were then taken into account. In addition, comparisons between recorded responses were also conducted.