This paper presents the results of experimental studies which were carried out to investigate residual properties of heat-treated concrete mixes made with recycled aggregates by adding fly ash. Mixes made with natural aggregates were used as control mixes. Concrete cylinders made of both types of mixes were employed in the experimental programme. The cylinders were heat treated at temperature varying from 100°C to 1000°C in increments of 100°C and were tested in compression and tension to determine their respective residual strengths. The residual strengths of both types of mixes followed a similar pattern of reduction at higher temperature exposure. The residual compressive stress and elastic modulus became nearly 15% at 900°C and 700°C, respectively. A slightly higher mass loss was observed in RAC mixes due to the use of recycled aggregates which contained more free water and sustained larger thermal deformation on heating at high temperatures.

Purpose: Disaster management information systems (DMISs) have been proposed in different parts of the world for effective response to a disaster. The purpose of this paper is to: compare design approaches of these DMISs; examine similarities in the design of databases and communication infrastructure; and draw conclusions. Based on the examination of the studies, future opportunities have been identified and discussed.Design/methodology/approach: The studies in the available literature on the designs of automated DMISs have been reviewed in the presented paper to identify similarities in design premise, conceptual design and design considerations.Findings: The examination of the available studies indicates that the research on DMIS has increased significantly in different countries of the world since 2004. Data of baseline information and available resources are required by most of the presented studies, as these data are necessary for effective response to a disaster. The communication infrastructures suggested include local area network, wide area network and satellite communication for better coordination between the responders and different relief agencies at different locations. The connectivity to these networks is possible through Ethernet, Wi-Fi, general packet radio service or satellite.Research limitations/implications: Although the research on DMIS has increased significantly over the last one decade, the studies are still few in numbers. Similarly, only few of the proposed systems have been developed and tested during a real disaster.Practical implications: The presented review of available studies provides a holistic view of the proposed DMISs which could be useful to the disaster management authorities.Originality/value: The paper provides valuable information on the differences in the proposed DMISs. This can help in identifying the gaps for future improvements for increased effectiveness of a DMIS. The future opportunities have also been identified in the presented paper and are discussed.

Fire following earthquake possesses significant risk of damages to life and property in urban areas. Mitigation and planning can reduce the level of risk associated with post-earthquake fire spread. This paper presents the details of a model that can be used to simulate mass urban fire spread based on the building material. The mechanisms of fire spread both within a building and building to building have been considered. For modelling building-to-building fire spread, the effects of direct flame impingement, heat transfer by convection and radiation, and flaming brands have been included in the model. A cellular automata scheme of modelling was employed for the construction of model. The model was implemented using a free-source computer programming framework which allows integration of building information data in geographic information system and mathematical formulation of fire spread mechanics. The results of the model have been compared with the existing data of mass urban conflagration. The employed algorithm was found to be stable which eliminates the need of large number of iterations to obtain reliable predictions. The results of the model correlated well with the existing data of fire-related damages and extent of fire spread available in the literature.

The details of experimental testing of thermomechanically treated reinforcing bars at elevated temperatures are presented in this paper. Rebars of 10-, 12-, 16-, 20-, and 25-mm diameter were used in the testing program. An electrical furnace was used to heat the bars to 100°C–900°C in increments of 100°C. The chemical composition of the rebars complied with bar manufacturing standards. The effect of bar diameter on the mechanical properties was random at ambient temperature, which also followed for the testing at elevated temperatures. These differences were due to the differences in the bar chemical composition. The yield plateau of the 25-mm-diameter bar disappeared on heating at 100°C, whereas this phenomenon occurred at 300°C for the rest of the bars. The rebar ultimate strength up to 300°C was higher compared with the strength at ambient temperature owing to blue-brittleness effects. The reduction coefficients for the proportional and yield strengths and the elastic moduli for all bars were similar at all heating temperatures. Brittle behavior of the bars tested at high temperatures was observed relative to the ambient temperature up to 500°C, which changed to ductile behavior thereafter. The suggested models to predict stress–strain curves for the strain-hardening region provided a reasonable match with the average observed curves for the bars tested at both ambient and elevated temperatures.