Showing papers in "Construction and Building Materials in 2012"

TL;DR: A series of investigations on the mechanical property, durability, and structural performance of recycled aggregate concrete (RAC) have been carried out in the past 15 years (1996-2011) in China.

TL;DR: In this article, the authors report recent advances in the knowledge base relevant to the durability of steel reinforced concrete in chloride environments, including: the role of mineral admixtures in concrete durability, the methods of measuring the chloride ingress into concrete, the challenges in assessing concrete durability from its chloride diffusivity, and the service life modeling of reinforced concrete.

TL;DR: In this article, the history, benefits, applications, and possible executive problems of using different types of natural and/or synthetic fibers in soil reinforcement through reference to published scientific data are reviewed.

TL;DR: In this article, the possibility to use silica gel or polyurethane as the carrier for protecting the bacteria was investigated, and it was shown that silica-gel immobilized bacteria exhibited a higher activity than polyurehane-incapacitated bacteria.

TL;DR: In this paper, a review of the possible mechanisms for self-healing phenomenon in cementitious materials, which are summarized based on substantial experimental studies and practical experience, are reviewed.

TL;DR: In this paper, the effect of colloidal nano-silica on concrete incorporating single (ordinary cement) and binary(ordinary cement+class F fly ash) binders was investigated, and the experimental program included tests for adiabatic temperature, rapid chloride ion permeability, mercury intrusion porosimetry, thermogravimetry and backscattered scanning electron microscopy in order to link macro and micro-scale trends.

TL;DR: In this paper, a review on the recycling of plastic waste as aggregate in cement mortar and concrete productions is presented, which is divided into four different sections along with introduction and conclusion sections.

TL;DR: In this article, the effects of incorporating Class F fly ash in the concrete mix design to mitigate the lower quality of recycled aggregates in concrete is presented, and the results show that one of the practical ways to utilize a high percentage of recycled aggregate in concrete, is by incorporating 25-35% of fly ash since some of the drawbacks induced by the use of recycled aggregation in concrete could be minimized.

TL;DR: A review of the literature about the durability of alkali-activated binders is presented in this article, focusing on resistance to acid attack, alkali−silica reaction, corrosion of steel reinforcement, resistance to high temperatures and to fire, and resistance to freeze-thaw.

TL;DR: In this paper, the performance of concrete containing polyethylene terephthalate bottles (PET) and polypropylene rubber (PPB) has been investigated and the effect of waste treatments, the size of waste particles and the waste replacement volume on the fresh and hardened properties of concrete.

TL;DR: In this paper, the authors highlight the importance of earth construction and highlight the environmental benefits associated with it, including economic issues, non-renewable resource consumption, waste generation, energy consumption, carbon dioxide emissions and indoor air quality.

TL;DR: In this paper, the feasibility of utilizing copper mine tailings for production of eco-friendly bricks based on the geopolymerization technology was studied, which neither uses clay and shale nor requires high temperature kiln firing, having significant environmental and ecological benefits.

TL;DR: In this paper, the effects of nano-silica (NS) on rate of cement hydration, setting time and strength development of concretes with about 50% fly ash or slag were evaluated.

TL;DR: In this article, a comparison between the static and dynamic moduli of CFRC beams was conducted, and it was found that CFRC with a fibre length of 5 cm and a fibre content of 5% has the best properties.

TL;DR: In this article, the use of milled waste glass, as partial replacement of cement, is estimated to produce significant gains in strength and durability of recycled aggregate concrete, which is also found to suppress alkali-silica reactions.

TL;DR: The effects of activation conditions on the engineering properties of slag/metakaolin blends are examined in this article, showing that at high activator concentration, compressive strength at early age is enhanced by the inclusion of metakaolin in the binder.

TL;DR: In this article, the influence of Sporoscarcina pasteurii bacteria on the compressive strength and rapid chloride permeability of concrete made without and with fly ash was evaluated.

TL;DR: In this article, the effects of steel fibres on the tensile and compressive strength, modulus of elasticity and post-cracking behaviour at different ages were investigated.

TL;DR: In this article, the influence of nano-silica agglomeration on microstructure and properties of the hardened cement-based materials was investigated by using precipitated silica (PS) with very large agglomers and fumed silica with much smaller ones as nanoscale additives.

TL;DR: In this paper, the authors examined experimentally the mechanical properties and permeability characteristics of the interface between normal concrete (NC) substrate which represents old concrete structures and an overlay of ultra high performance fiber concrete (UHPFC) as a repair material.

TL;DR: In this paper, the compressive strength of the mixture of kaolin and alkali activator was analyzed and the results showed that compressive strengths were affected by both S/L and Na2SiO3/Na2O ratios and strength increased with ageing day.

TL;DR: In this article, waste glass was ground and used in mortar as a partial cement replacement (0, 10% and 20%) material to ascertain applicability in concrete, and an extensive experimental program was carried out including pozzolanic activity, setting time, soundness, specific gravity, chemical analyses, laser particle size distribution, X-ray diffraction and scanning electron microscopy (SEM) on WGP and resistance to alkali silica reaction (ASR), chloride ion penetration resistance, absorption by capillarity, accelerated carbonation and external sulphate resistance on mortar

TL;DR: In this article, the effect of different concentrations of long multi-walled carbon nanotubes (MWCNTs) and short MWCNTs ( aspect ratio of about 157) in cement paste was investigated.

TL;DR: In this article, the mechanical and dynamic properties of self-compacting rubberized concrete (SCRC) were experimentally investigated, where crumb rubber from scrap tyres was used as a partial replacement for Fine Aggregate, Coarse Aggregate (CA), and combined Fine and Coarse aggregate (FCA) at 5, 10, and 15-wt% proportions.

TL;DR: In this article, a critical review of existing nondestructive testing (NDT) measurements is performed to assess on-site strength of concrete and the key factors influencing the quality of strength estimate are identified.

TL;DR: A review of the main aspects involved in WMA technology, including constituent materials, mix design and mechanical performance issues, as well as technological specificities, is presented in this paper.

TL;DR: In this paper, the novelty of using waste cooking oil (WCO), which is frequently found as a polluting waste material in landfills and rivers from the food industry, to rejuvenate the bituminous binder was investigated.

TL;DR: In this article, the efficiency of external strengthening systems for reinforced concrete beams using FRP fabric (Glass-Carbon) is examined. And an analytical model to predict the flexural failure of strengthened concrete elements is also developed.

TL;DR: In this paper, a unified stress-strain model of concrete for circular, square, and rectangular columns confined by fiber-reinforced polymer (FRP) jackets is presented.

TL;DR: In this paper, the performance of concrete mixtures containing local metakaolin was investigated in terms of compressive strength, water penetration, sorptivity, salt ponding, Rapid Chloride Permeability Test (RCPT) and electrical resistivity at 7, 28, 90 and 180 days.