In this article, a Dynamic Material Flow Analysis (DMFA) model is presented that characterizes the stocks and flows of cement from 1963 to 2063 in Iran. Using cement consumption data for the period of 1963-2018 an attempt is made to provide reliable estimates of the present as well as future cement in-use stocks and discards (from 2019 to 2063) to relevant stakeholders such as the Ministry of Road and Urban Development, Department of Environment, public and private utilities, and the construction and cement industries. Based on a normal lifetime distribution, a flow dynamic model is developed for each cement end-use category including buildings, infrastructures and others. Each sub model is simulated with 9 scenarios made from combinations of 3 scenarios for future cement consumption growth rate and 3 scenarios for the mean lifetime of the structures. For the base scenario, the model-derived estimate of in-use cement stock and cumulative discard for the year 2063 is 2191 million metric tons (Mt) and 1856 Mt, respectively. Such a great discard should be considered in policy making for better life cycle management of cement in Iran. The main finding of the paper is that by increasing the mean lifetime of the structures (especially buildings), the amount of cumulative cement discard in 2063 can be drastically decreased (generally over 50%) and this decrease will not be affected considerably by the cement consumption growth rate in the future. So this can be a reliable strategy for the sustainable life cycle management of infrastructures in Iran.

The deterioration of existing road pavement surfaces over the years due to aging and the growing number of heavy vehicles has become an important issue. Roads require appropriate maintenance to keep providing the target service. Many efforts have been made by road engineers to maintain road pavement surfaces; however, there are some problems due to costs, including vehicle running costs. Therefore, there is a need for an efficient and low-cost system to facilitate evaluation of the serviceability of existing road pavement surfaces. This study aims to develop an efficient, rational and useful method or system that can be used to perform a visual assessment of the condition of not only the pavement but also road structures, including slopes, vegetation and equipment such as guardrails, curbs and guideposts. Such a system should be inexpensive and be IT-based by making use of new information and the latest technologies. In addition, a method based on an analytic hierarchy process is employed in the decision-making process to analyze a complicated decision problem based on video files obtained by the system.

In this study, the seismic response of tall concrete structures with a special dual frame-wall concrete system is investigated using the endurance time method, and the results are compared with nonlinear time history analysis results. For this purpose, first, appropriate analytical models including buildings with concrete framed-wall system and 20, 30, and 40 stories are modeled non-linearly in PERFORM 3D software, and then, main nonlinear time history analyses are carried out for seven ground motions (accelerogram) further from the fault based on the FEMA P695 code and the endurance time accelerogram of (in) series. The results of the analysis are compared using indices (shear, relative displacement, and acceleration). The results indicate that the endurance time method is accurate in two indices of shear and acceleration, but the accuracy of the relative displacement index of the floor decreases as the number of stories of the structure increases.

Bridges play a critical role in the transportation system network; accordingly, assuring satisfaction with the service level of these structures is vital for bridge maintenance managers. Thus, it is vital to determine the optimum bridge maintenance plan (i.e., the optimum timing and type of repair activities applied to the bridge elements) considering the budget limitations. To optimize the bridge maintenance plan, some researchers have focused on developing optimization models, including the Genetic Algorithm (GA). However, a few studies have employed Bridge Information Modeling (BrIM) to enhance bridge maintenance management. This study focuses on developing an integrated framework based on BrIM and bridge maintenance optimization to utilize visualization capabilities of BrIM to assist maintenance managers in making decisions. The presented framework optimizes the bridge maintenance plan at the sub-element level. The BrIM automatically feeds into the developed GA optimization system. The introduced framework is successfully verified using a real-world case study.

reinforced concrete structures in these are as exposed to chloride aggressive marine environments. Therefore, it is important to provide protection and offer appropriate repair methods of buildings vulnerable to the degrading effects of corrosion. The present study sets out to identify and evaluate the causes and extent of corrosion observed in piers Imam Khomeini port. The microsilica is used to reduce corrosion. In order to achieve the above-mentioned goals, a number of experimental field tests were performed to determine the level of concrete condition in terms of reinforcement corrosion. Some tests were conducted to determine the conditions concrete piers in terms of reinforcement corrosion. Then a reinforcement corrosion density test is performed by using Potentiostat test involving a placement process; with different water-to-cement ratios and superplasticizers, the microsilica content was 5%, 10%, and 15%. And microsilica can serve as an alternative to cement and was measured according to ASTM standards. Microsilica was exposed to aggressive conditions at different periods and a concrete compressive strength test was performed. The results show that the compressive strength and corrosion resistance of the concrete increased for concrete mixture containing 10% microsilica with a water-to-cement ratio of 34% and a superplasticizer ratio of 6

This paper presents the results of an experimental investigation on three different aspects of cement mortars incorporating amorphous carbon powder; rheology, strength and water absorption. Amorphous carbon powder is a by-product of the paraffin industry and was replaced with 0, 4, 6 and 8% of aggregate. Rheological tests were conducted immediately after mixing procedure, the strength of mortars was investigated by two methods; compressive and flexural at the age of 7 and 28 days. Furthermore, the water absorption of specimens was determined. Using Amorphous carbon powder was detrimental in terms of workability. However, after 28 days compressive and flexural strengths increased and water absorption declined with the addition of amorphous carbon powder, thus reducing the risk to degradation over time in severe environments.

In this paper, the performance of soil nailed walls with various nail patterns has been studied to find an optimum layout based on the deformation criterion. To this end, parametric analysis on soil nailed walls with various nailing patterns was performed. Nine patterns including one uniform and eight variable nails length were considered. For each pattern, parametric analysis on different parameters including wall height, surcharge, nails spacing was done to find an optimum pattern based on the deformation criterion. The simulation results indicate that using the variable layout with long nails at the top of the wall not only reduces the lateral deformation of soil nailed wall but also decreases the density of nails.

The implementation of Building Information Modeling (BIM) in the Architecture, Engineering and Construction (AEC) industry is growing rapidly. The Oil, Gas and Petrochemical industry (OGPi), however, is still lagging in harnessing the BIM capabilities. Therefore, the main question of this research is: How and what actions should be adopted for deploying BIM in the OGPi? The research is divided into three parts as an action research. This study investigates the second part, namely preparation of an adoption roadmap for deploying BIM in collaboration with Integrated Project Delivery (IPD) in the OGPi. To achieve this goal, the extensive literature review including the most established roadmaps in the AEC industry and also the semi-structured interviews with the OGPi's experts were conducted. In this part of the research, an adoption roadmap is derived for OGPi via Innovation Diffusion Theory (IDT), ‘Why, How, What’ questions (Sink model), strategic planning and innovation roadmap as well as the iterative process in the studies and interviews. The prepared roadmap validated by triangulation through focus group meetings and oils the wheels of BIM implementation alongside with IPD in the OGPi firms to grabs BIM merits and harness its challenges. Finally, the major limitations and the required future studies are addressed.

Road accidents are one of the ten major causes of death in the world. Lack of enough friction and skid resistance of the pavement surface are known as important factors in traffic accidents. In this study, to evaluate the relationship between skid resistance and pavement surface macrotexture, five methods of creating macrotexture on concrete pavements were used. Sand Patch test, British Pendulum and Wide Wheel Abrasion tests were employed to obtain mean texture depth, skid resistance and abrasion resistance of the surface, respectively. Results showed that brushing on fresh concrete surface (parallel or perpendicular to the traffic direction) can improve frictional properties of pavement surface, drastically. This method increased British Pendulum Number (BPN) and friction coefficient by 32% and 38% (in average), respectively. Friction coefficient of parallel brushing was quite similar to perpendicular (0.2% discrepancy), while its abrasion resistance was 4% higher. Hence, as a finding, parallel brushing is the most recommended texturing technique in respect to friction. Generally, concrete pavement texturing decreases surface abrasion resistance, but burlap dragging improved this index by 2.5%. Nevertheless, burlap dragging results could be deceptive due to the high sensitivity to initial setup conditions. In other words, measurement scale of the studied testing procedures are small in respect to the scale of protuberances caused by burlap dragging method.

The determination of tunnel support, required for tunnel stability and safety, is an important debate in tunnel engineering field. Q-system classification is a technique used to determine the support system of a tunnel in rock. The problem is that all required parameters of support system are not accessible. On the other hand, such accesses are very costly and time consuming. Therefore, it is impossible to determine the Q-value in all cases. This paper identifies the most influential parameters of Q-system using SPSS program. Then, it adopts multi-variable regression (MVR) and genetic algorithm (GA) methods to propose a relation for predicting the Q-value using three influential parameters. To this end, 140 experimental data are used. To assess the obtained models, 34 new experimental data, which are not in the primary dataset, are used. The innovation of this paper is that instead of six parameters, the Q-value is determined using three parameters with the highest impact on it instead of six parameters. In this study, the MVR model, with RMSE=2.68 and correlation coefficient=0.81 for train data and RMSE=2.55 and correlation coefficient=0.80 for test data, showed better performance than GA model, with RMSE=2.90 and correlation coefficient=0.82 for train data and RMSE=2.61 and correlation coefficient=0.84 for test data.