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Colored self-compacting mortar (C-SCM) is a novel cementitious product that has been recently used in decoration and rehabilitation and has improved aesthetic quality of architectural constructions. C-SCM is susceptible to strength decrease due to excessive pigment presence in the mixture. Optimum pigment content with respect to color intensity and mechanical performance is an important matter that should be determined to prevent mortar failure after construction. In this research, two inorganic pigments in production of colored self-compacting mortar were utilized. The impact of titanium dioxide (TiO2) and iron hydroxide (FeO(OH)) contents on behavior of C-SCMs were investigated in white and gray cement matrixes. Experiments included measurements of compressive strength of mortar cubes and cylinders, flexural strength and colorimetric properties. Analyses on compressive and flexural toughness were applied, as well. It was concluded that pigment content in mix design of colored self-compacting mortar could be optimized with regard to color quality in surface and mechanical strength of the product. Results implied that 5 and 2% of titanium dioxide were the saturation points of color and strength respectively and iron hydroxide at 10% was unsurpassed in C-SCMs containing white cement. Application of both pigments in gray SCMs caused the saturation points of color and strength to occur at 10 and 2%, respectively.

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Compressive strength is as one of the most important properties of concrete and mortar that its measurement may be necessary at both early and later ages. Prediction of compressive strength by a proper model is a fast and cost-effective way for evaluating cement quality under various curing conditions. In this paper, a logarithmic model based on the results of an experimental work conducted to investigate the effects of curing time and temperature on the compressive strength development of chemically activated high phosphorous slag content cement has been presented. This model is in terms of curing time and temperature as independent variables and compressive strength as dependent variable. For this purpose, mortar specimens were prepared from 80 wt.% phosphorous slag, 14 wt.% Portland cement, and 6 wt.% compound chemical activator at Blaine fineness of 303 m2/kg. The specimens were cured in lime-saturated water under temperatures of 25, 45, 65, 85 and 100 ºC in oven. The model has two adjustable parameters for various curing times and temperatures. Modeling has been done by applying dimensionless insight. The proposed model can efficiently predict the compressive strength of this type of high phosphorous slag cement with an average relative error of less than 4%.

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Fiber Reinforcement Concrete is mainly distinguished in their behavior in cracked tension zone which is called tension softening behavior. Wide researchers have been investigated this behavior and present many tensioned softening models. This paper presents a compression between four tension softening models including constant, linear, bilinear and exponential models in flexural behavior. In this study the behavior of rectangular beam section under four/three point bending test have been predicted by iteration procedure. These models has been compared in some parametrical properties. The result of this study shows variety in result for four used models and indicate concern in applied assumptions.

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The present study demonstrates the influence of operating speed on capacity of a midblock section of urban road. Speed – flow data collected at 12 midblock sections of 6-lane and 4-lane divided urban arterials in four metropolitan cities of India are analyzed to determine their capacity. Lane capacity was found to vary from 1482 pcu/hr to 2105 pcu/hr. This variation is explained on the basis of city size and driving behavior, which would influence the free flow speed on the road. Free flow speed was also measured at each section and these speed data were used to determine operating speed (85th percentile of free flow speed of standard car) on the road. Lane capacity was found to be strongly related with operating speed on a road and a second degree polynomial model is developed between the lane capacity and operating speed. This model is further validated by collecting speed flow data at two new sections and their capacity was estimated from field data and from the model developed in the study. The predicted capacity was found to be matching with field capacity and the maximum error was 0.10 percent. Operating speed on a road can vary due to road surface condition, side friction or similar other factors. All these will have influence on capacity of the road. The capacity model suggested in the present study can be a useful tool to determine capacity of an urban road from its operating speed data.

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The present paper addresses the comparative study of two adjacent single-degree-of freedom structures for elastic and inelastic systems with and without pounding and also in the presence and absence of TMD under seismic excitations. The tuned mass damper considered for the present study is a passive device attached to single main structural unit in the form of weak storey at the top of main system. Total eight models have been considered depending upon the presence and absence of pounding as well as TMD in the analysis. The entire numerical simulation is carried out in time domain by considering the inputs of four real earthquake ground motions. An elastic adjacent structural system always overrates the pounding forces than the inelastic adjacent structural units. The use of TMD reduces the pounding forces in the adjacent structures. In pounding, structural displacement response is much sensitive for inelastic systems mostly under consideration or ignorance of TMD. Structural energy formation in the adjacent structures shows much variation with and without consideration of pounding as well as TMD.

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Construction industries are the most dangerous worksites with high risk of occupational accident and bodily injuries, which ranges from mild to very severe cases. The aim of this study was to explore the causal factors of accident severity rate (ASR), in 13 of the biggest Iranian construction industries. In this analytical cross-sectional study, the data of registered accidents from 2009 until 2013 were obtained from an official database. Data of HSE risk management systems and HSE training were also gathered from comprehensive accident investigation reports. Data analysis and regression modeling were done using SPSS statistical software (version 22). The mean and SD of ASR of studied construction worksites was 257.52±1098.95. The results show that the system associated with HSE and HSE risk management established only 41.8 and 18.4%, respectively. The results of multiple linear regression indicated that some individual and organizational factors (IOFs), HSE training factors (HTFs), and Risk Management System factors (RMSFs) were significantly associated with ASR (p<0.05). The study revealed the causal factors of ASR. Hence, these findings can be applied in the design and implementation of a comprehensive HSE risk management system to reduce ASR.

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One of the main concerns in an essential or highly important building is finding the appropriate structural system, while the efficiency of each conventional structural system varies in different cases. In this paper a new multi objective structural configuration is proposed and its efficiency for protecting buildings against the multi-hazards including earthquake, explosion and typhoon is shown in a case study of a 10 stories building sample. To create the optimum and efficient configuration of the structural elements, and to make some large spans, a configuration including Vierendeel girders is used. In this type of configuration, the inner suspended floor parts protect the outer elements by balancing perimeter span loads. This system makes a new condition for the building to be protected against the progressive collapse due to the terrorism attacks. Furthermore, the partially suspended floors in special stories act like tuned mass dampers (TMDs), which are suitable to decrease the amplitude of the displacement response of the structure during an earthquake.

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During the entire life cycle of a pavement, highway agencies are expected to maintain adequate surface frictional properties to facilitate traction between car tires and pavement surface. Traditionally the repair method for a friction-deficient pavement surface is the application of a new surfacing layer. The monitoring and remedying practice is important however, it is a passive approach toward the problem. A more proactive approach would be to test the hot mix asphalt in the laboratory during its initial mix design stage to ensure that aggregate combinations used in the asphalt pavement will provide adequate friction over the life of the pavement. Toward this objective the polishing behavior of laboratory-prepared HMA specimens made of eight different job mix formulas has been studied in terms of friction values. In addition, a robust statistical analysis of the obtained surface friction values has also been carried out in an attempt to verify the success in developing this new asphalt polisher that is used to simulate the tire-pavement interaction. Furthermore, polishing behavior (i.e., polishing trend, rate of friction loss and absolute and percent values of decrease) were all fully investigated to capture surface frictional deterioration of HMA specimens. In conclusion, the new asphalt polisher showed a good degree of repeatability. Additionally, it has been concluded that the decrease in polish number is maximum during the first hour of polishing. With the passage of time the drop in friction decreases and stabilizes.

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Pedestrians are among one of the most vulnerable road users. Speed of vehicles is considered as one of the major causes of danger for pedestrians crossing the street (making cross movements). Therefore, it is of utmost importance to devise suitable solutions for reducing speed of vehicles. One of these solutions is installation of Pedestrian Refuge Islands (PRI) in very wide midblocks. With regard to fluctuations in pedestrian and vehicle traffic volume in traffic hours, there are different variations in collisions between vehicle and pedestrian. In this article the effect of constructed PRI in Tehran on speed of vehicles and consequently their effects on probability fluctuations of fatal accidents are determined. Speed of vehicles in two phases of before and after arriving to the PRI is assessed. Additionally, speed of vehicles in non-observed volumes of vehicle and pedestrian are calculated using Aimsun.v6 simulation software. Paired T-test is applied to compare average speed of vehicles before and after the PRI. The results revealed that except for traffic volumes of 3000-4000 veh/h and 400-600 ped/h in other volumes reduction of average speed of vehicles as a result of PRI is significant. Also, the results show that in all volumes, these equipments reduce the probability of fatal accidents to under 10%. According to the results, it is recommended that PRI should be installed in midblocks where traffic volume of vehicles in each lane is less than 750 veh/h.

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The gap acceptance behavior of drivers at U-turn median openings is studied by considering the critical gap which cannot be obtained directly by field measurements. A thorough investigation on critical gap estimation is carried out by collecting the data sets from median openings at 4-lane, 6-lane and 8-lane roads of Hyderabad City, India. Wide difference (10% - 42%) among the critical gap values estimated by the application of existing methods shows the limitation to consider for the mixed traffic situations. In order to address this issue, recently developed method Influence Area For Gap Acceptance (INAFOGA) which is based on clearing behavior of drivers at unsignalised intersections is modified and applied considering the merging behavior of U-turn vehicles at median openings and named as ‘Modified INAFOGA’ method. Modified INAFOGA method is compared with probability equilibrium method through paired-sample hypothesis (t-test) and result revealed that difference in mean values 0.009 signifies that both methods are comparable. Difference in critical gap values obtained from the box plots and radar charts indicates that Probability equilibrium method is not suitable to address the behavior of U-turn vehicles at median openings under mixed traffic conditions. These observations coupled with higher critical gap values validate the fact that ‘modified INAFOGA’ method is indeed appropriate under mixed traffic conditions.

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The fresh properties of Self Compacting Concrete (SCC) might be more susceptible to quality and quantity changes of ingredients than conventional concrete because of a combination of detailed requirements, more complex mix design, and inherent low yield stress and viscosity. In spit of the low robustness of SCC, there are a few methods available to assess the SCC robustness that the accuracy of these methods has not been fully agreed. The current study provides an index for SCC robustness based on the rheology parameters. Thus, an experimental program was undertaken to evaluate the robustness of eight selected SCCs. For doing this, water content of each SCC was changed slightly and their fresh and hardened properties were measured. The results indicated that the length of rheology parameters curve due to variation of mixing water is able to assess the SCC robustness that is comparable with combined performance based on the workability tests changes. According to this index, the robustness of SCC increases about 10% by using air-entraining admixture (AEA) and decreases considerably by reduction the paste volume (up to about 5 times). Also, the most appropriate single workability test to assess the robustness is sieve segregation test. Moreover, the scattering of compressive strength results show that there is a level of robustness in fresh state that after that the scattering of results in hardened state can be affected.

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In recent times, Bus Arrival Time Prediction (BATP) systems are gaining more popularity in the field of Advanced Public transportation systems (APTS), a major functional area under Intelligent Transportation Systems (ITS). BATP systems aim to predict bus arrival times at various bus stops and provide the same to passenger’s pre-trip or while waiting at bus stops. A BATP system, which is accurate, is expected to attract more commuters to public transport, thus helping to reduce congestion. However, such accurate prediction of bus arrival still remains a challenge, especially under heterogeneous and lane-less traffic conditions such as the one existing in India. The uncertainty associated with such traffic is very high and hence the usual approach of prediction based on average speed will not be enough for accurate prediction. In order to make accurate predictions under such conditions, there is a need to identify correct inputs and suitable prediction methodology that can capture the variations in travel time. To accomplish the above goal, a robust framework relying on data analytics is proposed in this study. The spatial and temporal patterns in travel times were identified in real time by performing cluster analysis and the significant inputs thus identified were used for the prediction. The prediction algorithm used the Adaptive Kalman Filter approach, in order to take into account of the high variability in travel time. The proposed schemes were corroborated using real-world GPS data and the results obtained are very promising.