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Accurate estimation of the thermal stresses in rigid pavements is essential for the assessment of its service life. Thermal stress (an outcome of temperature differential) within the slab is significantly dependent on local weather conditions. This article presents a methodology for prediction of temperature profiles in rigid pavement. In this work, partial differential equations governing heat transfer through concrete pavement are numerically solved. The boundary conditions of the heat transfer model were formulated based on the real-time weather data. The temperature profiles predicted by solving the model were used to calculate the temperature difference between the top and bottom of the rigid pavement slab. The proposed methodology was implemented using 30 years of gridded weather data for whole of India. From the predicted temperature profiles, the annual ${\rm MPTD}$ M P T D and ${\rm MNTD}$ M N T D of the pavement slab were calculated. The mean values for each grid point observed over 30 years were used to develop temperature differential maps. The predicted values of maximum positive and negative temperature differentials had significantly higher values compared to the current codal recommendations of India. Developed maps can be used for estimating the design temperature differentials in places having similar climatic conditions presented in this study. Abbreviations: DLC: dry lean concrete; GSB: granular subbase; IRC: Indian Road Congress; MMMT: mean monthly maximum temperature; MMRH: mean monthly relative humidity; MTD: maximum temperature differential; MPTD: maximum positive temperature differential; MNTD: maximum negative temperature differential; PDE: partial differential equation; PQC: pavement quality concrete; SG: subgrade; TD: temperature differential [ABSTRACT FROM AUTHOR]

Due to Infrastructure development city streets are being covered with concrete pavements in which it makes the pavement surface impermeable. During monsoon period, the importance of counter action against the stormwater runoff develops a stress among the Central and the State Governments of India. It also attracts the attention of the Road and Transport officials mainly because of the difficulties faced with poor drainage system during heavy intensity of rainfall. The productive application of pervious concrete includes its usage for light volume transportation and it also diminishes the additional design for stormwater drainage. This concrete also holds potential to accommodate shoulders in heavy traffic roadway transportation. The behaviour of pervious pavement under various loading scenario can be well understand using Finite Element Method Analysis (FEMA). For primary assessment of pervious concrete (PC) as pavements, computer modelling software is preferable and economical comparing to ground evaluation after installation. In this paper, a EverFE (Finite Element Analysis) tool has been used to develop and determine the loading characteristics of pervious pavement based on the experimental values obtained through preliminary studies. [ABSTRACT FROM AUTHOR]

Thermal power plants in India produce a large quantity of fly ash, which is harmful to the environment. Underutilization of fly ash and the scarcity of natural minerals have created the need for an unusual construction strategy to prevent huge waste dumps on valuable land and to preserve fast-depleting resources. A study was conducted to determine the efficacy of lime-stabilized fly ash blended with quarry fines as flexible pavement subbase materials. The laboratory investigations were conducted to determine compaction characteristics, unconfined compressive strength, California bearing ratio (CBR), and durability to obtain the optimal quarry fines, fly ash, and lime (QFL) mix. The durability of QFL mixes was studied using 12 wetting–drying cycles. Using the strength and durability criteria specified by the Indian Road Congress, the optimum mix proportion of 40Q:60F+3L was determined. Pavement analyses were performed using the IITPAVE program. The QFL mix was observed to be superior to conventional granular subbase (GSB) layer material in terms of service life and cost-effectiveness. A field investigation was carried out on trial test sections constructed using the optimum QFL mix and GSB in the subbase layer of pavement. Field dry density and dynamic cone penetrometer (DCP) tests were performed on the compacted subgrade and subbase layers to assess the desired quality assurance in the construction of test sections. The early structural performance assessment of pavement sections using a falling weight deflectometer (FWD) test indicated that QFL could effectively replace conventional GSB. [ABSTRACT FROM AUTHOR]

Concrete being one of the most extensively used material worldwide, the ecological influence of the manufacture of the raw materials for concrete is substantial. The scale of the problem makes it essential to examine other sources of raw materials to minimize the consumption of available natural resources. Since more than 70% of the bulk of conventional concrete consists of aggregates, maximizing the use of alternate/waste materials brings remarkable benefits such as a decrease in the demand for natural aggregates and saving energy costs related to natural aggregate production and conveyance. India, the second-largest consumer of crushed aggregates in the world, is making great strides in using waste/recycled materials as aggregates in pavement construction. Every year, millions of tons of reclaimed asphalt pavement (RAP) are being produced from the repair and reconstruction of existing roads. If this waste material can be reused without much processing in the construction of new pavements, it could be a great alternative to natural aggregates. This paper is intended to examine the flexural fatigue behavior of RAP-based concrete with and without steel fibers. The study considers varied proportions of RAP content (0% to 30%), fiber content (0% and 1%), and stress levels (0.9, 0.8, and 0.7). A total of 96 prismatic samples were examined under static and flexure fatigue load. The frequency for the fatigue loading was kept at 2 Hz, maintaining a stress ratio at 0.1. The results indicate a decrease in flexural fatigue life with an increase in the RAP content at all the stress levels. However, there is a substantial enhancement in fatigue life when steel fibers are added to RAP-based concrete. The results show that two-parameter Weibull distribution is the best fit for modeling fatigue life variation. The fatigue strength (at a survival probability of 0.9, corresponding to two million load repetitions) decreased by 9%, 18%, and 23% for RAP contents of 10%, 20%, and 30%, respectively. The addition of fibers enhanced the fatigue strength of RAP-based concrete by 50%–65%. [ABSTRACT FROM AUTHOR]

India is the second largest producer of cement in the world with an annual production of 455 Million Tonnes (MT) which is expected to reach up to 550MT by 2020. In India, the increased demand for cement in the construction industry is required to meet the needs of infrastructure development. However, the production of Portland cement releases significant amounts of CO2 to the atmosphere. Therefore, it is necessary to look for sustainable solutions for concrete production by the use of supplementary cementitious materials. The alternative replacement for Ordinary Portland Cement (OPC) can be Ground Granulated Blast Furnace Slag (GGBS), Fly-ash, Silica fume, Rice-husk ash, which is the various industrial by-products. In this present work, an attempt was made to develop Alkali Activated Slag Concrete (AASC) using Precious Slag (PS) ball as fine aggregate. The development of AASC was made with GGBS as the principal binder. Mixes were developed with binder content 443 kg/m³, Sodium Silicate (SS)/ Sodium Hydroxide (SH) ratio of 1 and their performance when exposed to ambient temperature were studied. Alkali binder ratio (0.3) with 8, 10, 12 and 14M NaOH was selec ted for all the AASC mixes. The test results showed that the slump values for the different mixes satisfying the MoRTH guidelines for concrete pavements. The AASC mixes have higher compressive strength ranging between 41-64 MPa. The fatigue life of the AASC mix was has improved by the addition of PS ball, at the higher concentration of NaOH. [ABSTRACT FROM AUTHOR]

• Permeability and pore structure of the porous concrete mix was checked with over burnt brick aggregate. • A nonlinear relationship was obtained between permeability and porosity of porous mix. • Minimum permeability for single sized and dense graded aggregate was found to be 0.5 cm/s and 1.4 cm/s, respectively. • An increase in aggregate size leads to the increase in permeability. • Kozney-Carman model for permeability is modified for over burnt brick aggregate. The scarcity of regular construction material has always been a challenging concern in some of the North-Eastern states of India like Tripura. To meet this inordinate shortage, brick aggregate has earned an immense attention due to its availability and low cost. The main purpose of this paper is to correlate the pore structure and hydraulic conductivity of the porous concrete matrix using brick aggregate to meet the insufficiency of conventional aggregates. Pervious concrete pavement, due to its eminence as an eco-friendly pavement system, has become an emerging technology in the developed and developing countries. In this paper, a series of pervious concrete mixes are made with over burnt brick aggregate and the porosity and permeability are evaluated. Water-cement ratio, aggregate size and the presence of fine aggregate in the porous mix are chosen as the mix variables and their contributions in controlling the permeability is quantified. A relationship is then drawn between permeability and the pore features considering the relative mean pore size and pore tortuosity. A modified Kozney-Carman model for pervious concrete is also developed using the investigational test results and the predicted equations. The predicted values and the developed relationships provide a very good agreement with experimental test results. [ABSTRACT FROM AUTHOR]

Abstract: Nondestructive testing plays an important role in identifying and detection of internal defects and cracks in many industrial applications such as concrete structures, pavements, and metal testing. Nondestructive testing of concrete allows the inspection of larger areas of concrete members at lesser cost than coring and provides more information than visual inspection. The deterioration of reinforced concrete structure such as elevated service reservoir is major problem in many countries of the world. Many of the existing water tanks in service today are inadequate to need the present water demand. To ensure safe durable service and selecting the most appropriate repair strategy it is essential to perform in situ inspection for a distressed concrete structure. The main objective of present work is to propose the developed systematic investigation for metrology and a condition ranking procedure based on Analytical hierarchy process (AHP). DER rating technique is used to find out the condition ranking of elevated service reservoir in Karad region in Maharashtra. The ranking assessment for elevated service reservoir structure has been carried our using different Non-destructive test methods like surface hardness, ultrasonic pulse velocity test, half cell potential methods and cover depth measure. [Copyright &y& Elsevier]

Plain jointed concrete pavements laid in Mumbai City (India) during the early 1990s were structurally evaluated using a falling weight deflectometer (FWD) and testing of concrete cores extracted from the pavement slabs. The ultrasonic pulse velocity (UPV) of the concrete in the cores was determined first and then the cores were crushed under compression. The pavement deflections were found to be within the limits as suggested in the Indian codes and the international literature. The joint conditions were also found to be satisfactory. The design strength of the concrete was back-calculated from the compressive strength of the cores and was found to conform to the design specifications. However, the construction quality was found wanting as the thickness of pavement slabs at a few locations was lower than that specified and it has resulted in cracking of the slabs. The dynamic modulus of elasticity of concrete as determined by the FWD was found to correspond well with that computed from the UPV of cores and from the compressive strength of concrete. A method is suggested to estimate the structural parameters of uncracked pavement slabs from the dynamic modulus of elasticity obtained through the indirect method of UPV testing which is less expensive compared to evaluation by the FWD. [ABSTRACT FROM AUTHOR]

Use of precast concrete pavement (PCP) for rapid construction of roads has gained high popularity in the last decade. In this technology, precast pavement panels are cast in a precast yard, transported to the construction site, placed on a prepared subbase, and connected using dowel bars. This paper describes one such application, reported for the first time in India. Planning, analysis, design, construction, and testing of a 24-m road length was discussed. An empirical equation was developed to obtain the stresses induced in the panel. It also includes an innovative load transfer mechanism (LTM) using a lateral dowel bar arrangement instead of the commonly used longitudinal dowel bar arrangement. This LTM is easier to implement, helps to maintain good riding quality, provides faster construction speed, and does not compromise the load transfer efficiency (LTE). The load transfer efficiency of the newly developed LTM was found to be 97% 6 months after placement of the panels. [ABSTRACT FROM AUTHOR]