One of the important issues in the production of Concrete is environmental variability that affects the Concrete and elements constructed from this material. Due to the importance of different characteristics of Concrete in short- and long-term conditions, this article aims to investigate the influence of initial temperature conditions of self-compacting Concrete on its long-term characteristics and determine the initial optimal temperature of Concrete. For these purposes, several experiments under three temperature conditions of 5, 20, and 40 degree-of-Celsius were conducted to evaluate the rheology and mechanical properties of fresh Concrete in the range of 7 and 28 days. In these experiments, alternative mineral admixtures of cement such as micro-silica, fly ash, and zeolite were used to build the Concrete specimens. Results demonstrate that the mechanical properties of the specimens increase with increasing initial temperature in the short term, while such properties significantly decrease in the long term compared to the specimens constructed under lower initial temperature. Moreover, the fluidity of self-compacting Concrete increases with increasing initial temperature.

Plastic hinge properties play a crucial role in predicting the nonlinear response of structural elements. The plastic hinge region of reinforced Concrete normal beams has been previously studied experimentally and analytically. The main objective of this research is to evaluate the behavior of the plastic hinge region of reinforced Concrete deep beams and its comparison with normal beams through finite element simulation. To do so, ten beams contain six deep beams, and four normal beams, under concentrated and uniformly distributed loading, are investigated. Lengths in the plastic hinge region involving curvature localization, rebar yielding, and Concrete crushing zones are studied. The results indicate that the curvature localization zone is not suitable for the prediction of plastic hinge length in reinforced Concrete deep beams. Based on the results it can be stated that in simply supported normal beams the Concrete crushing zone is focused on the middle span, but in simply supported deep beams by creating a compression strut between loading place and support, the Concrete crushing zone spreads along the compression trajectory. The rebar yielding zone of simply supported beams increases as the loading type is changed from the concentrated load at the middle to the uniformly distributed load.

In this study, the Concrete-steel bond strength of Concrete filled cylindrical steel tubes has been experimentally investigated. 22 short, high strength and normal Concrete filled circular steel tubes were tested. Push-out test was carried out as the common method to evaluate the bond carrying capacity. Four different Concrete mixes were used in preparing the specimens. The steel tubes were welded type with the nominal inside diameters of 3, 4, 6 and 8 inches. According to the test results bond strength increases with reduction of the w/c ratio of Concrete mixes. The high strength to normal Concrete bond strength ratio increases with the diameter of steel tubes. The bond strength decreases for higher diameters in both normal and high strength Concrete specimens.

Increasing impermeable levels has made water control a great challenge. On the other hand, the increase of impermeable surfaces causes the lack of heat exchange of the underground layers with the air, which will increase global warming. One solution to this challenge is to use porous pavements. Advantages of porous pavement compared to normal pavement,only on run-water control, he can easily increase the use of the road, increase the main road and increase the road, and so on. Restrictions on porous Concrete include restrictions on use on high-traffic roads or heavy traffic loads,In other words, with the current knowledge about this pavement system, it can be used in less traffic routes such as local roads and streets and parking lots. The purpose of this study is to investigate aerated Concrete and get acquainted with the standard related to aerated Concrete. Also in this research, the advantages and disadvantages of porous Concrete, construction, maintenance and common problems of this system have been required. At the end of this research, only to gain general knowledge about aerated Concrete and aerated Concrete pavement mix design, common maintenance methods of porous pavement and common tests in the relevant researches are introduced. In the end, it was concluded that with sufficient knowledge, porous Concrete pavement can be used on roads with low traffic or light traffic load.

A new method for seismic retrofitting Concrete structures is proposed using an X-shaped precast prestressed Concrete brace. This PPC brace is made of four precast Concrete parts and middle section that are assembled and added to the existing frame. This method has the following benefits: there is no need to work with wet Concrete in site or anchor and bolt to the existing frame, which may lead to a fast and economic retrofitting method. The X-shaped Concrete brace was made in half size and its efficiency is confirmed. That X-shaped precast prestressed Concrete brace was simulated and evaluated by computerized analysis using ABAQUS FEA modeling by authors of this paper earlier, and the proposed brace showed proper results in reducing lateral drifts and that method is considered as a proper method for seismic retrofitting. Here we are suggesting a different setup for the brace, which may lead to faster and more economic strengthening of RC structures. The new setup is omitting the middle section and suggests the brace to be used as a single diagonal. A model of this proposed method is simulated in ABAQUS FEA and the results show it is proper in reducing lateral displacements.