Bacteria-initiated self-healing concrete: Influence of chloride ions, carbonation and mechanical load

Under service conditions and because of environmental and climate changes, the concrete is at risk due to crack-induced durability problems. The consequences can be even more pronounced when concrete is exposed to specifically aggressive environmental conditions. This has been portrayed by rapid deterioration of relatively young concrete...

The competitive diffusion process of chloride into mortar immersed in chloride-sulfate solution

The chloride and sulfate exist together in real environment, no matter marine or salts lakes, and the ratio of the chloride to sulfate is varied. To precisely predict the concrete durability under real environment, this paper mainly investigated the influence of sulfate on chloride ions diffuse into hardened cement paste. The Minitab software...

The air permeability, carbonation and chloride content along a concrete highway underpass

In reinforced concrete structures carbonation and chloride ingress are two main phenomena that induce rebar corrosion. Agents such as CO2 gas or water containing chloride enter the cementitious material mainly throughout the pore system. The air permeability was measured with a non-destructive rapid test method. The aim of the present work was...

Durability-based design: the European perspective

In Europe, design for the durability of new reinforced concrete structures is currently based on a prescriptive approach. The design, execution (construction) and planned maintenance of a concrete structure have to lead to the intended level of safety and serviceability throughout its entire service life. This requires numeric models based on...

Molecular Dynamics Simulations of Non-Photochemical Laser-Induced Nucleation: Electrolyte Clustering by Nanoparticle Heating

Non-photochemical laser-induced nucleation (NPLIN) is a process where a crystalline phase is formed out of solution by exposure to a laser beam. In NPLIN, the nucleation probability is strongly dependent on the beam intensity and weakly dependent on the wavelength. NPLIN offers a feasible alternative to energy-intensive industrial...

Effect van variaties in chloride concentratie op de efficiency van een warmte- en koudeopslag systeem

This research is executed to study the effects of density driven currents and their effects on Aquifer Thermal Energy Storage Systems(ATES).<br/><br/>A monowell system is studied in the location of Amsterdam, in the Netherlands. Due to saline water deep in the ground and fresh water higher in the ground, there is a gradient in density in the...

Chloride transport in partially saturated mortar made of blended cement

Due to environmental (low CO2 emission) and economic benefit, supplementary cementitious materials (SCMs) have been widely used in reinforced concrete structures. However, the question from engineering practice is to which extend these blended mixtures do meet the future durability criteria. Chloride ingression is nowadays considered as the main...

Chloride diffusivity in partially saturated cement-based materials assessed by resistivity measurements

Concrete is seldom saturated due to its self-desiccation. Even the submerged concrete structures may remain unsaturated for quite a long time. It has been reported the saturation level of pore solution has significant effect on species penetration. However, very little work was proposed regarding the transport properties and serviceability of...

Guideline for service life design of structural concrete: A performance based approach with regard to chloride induced corrosion

Nowadays major structures require a service life of 100 years or even more. CUR committee VC81 has developed a guideline for service life design based on initiation of corrosion due to chloride penetration for exposure classes XD or XS. A semi-probabilistic simplification of the DuraCrete methodology is introduced with a probability of failure...

Effects of slag and fly ash on reinforcement corrosion in concrete in chloride environment: Research from the Netherlands

A review is given of research on the durability performance of concrete made with blast furnace slag and fly ash related to chloride induced reinforcement corrosion, carried out in the Netherlands, where slag has been used in cement for almost a century. Results are presented from field studies on concrete in marine environment and laboratory...

Prediction of Deterioration of Concrete Bridges

In the early 20th century, the general idea was that concrete structures would never show deterioration. However, in the 1990s concrete structures showed an increase in number of cracks and area of spalling. Especially spalling of the concrete cover could create a harmful situation to the users. Spalling of the cover is caused by corrosion of...

Toetsing van de chemische water- en bodemkwaliteit van de Westerschelde ten behoeve van het Evaluatierapport 2003

In het kader van het project ZEEMOVE worden de gevolgen van verruiming van de Westerschelde gemonitord en beschreven in het MOVE Evaluatierapport 2003. Binnen het project MOVE zijn hypothesen opgesteld om na te gaan in welke mate de chemische kwaliteit van het water en de bodem van de Westerschelde reageert op de bagger- en stortwerkzaamheden...

Durability of Marine Concrete under Thermal Cycling Loads

Data on chloride penetration into concrete exposed to a simulated aggressive marine environment are presented. Concrete specimens, large beams and small cubes, are subjected to 90 complete exposure cycles of wetting and drying plus heating and cooling. The applied exposure condition consists of a drying period of 42 hrs followed by a wetting...

3D-modellering van de waterbeweging en verblijftijdsspreiding ten behoeve van de inrichting van de Loenderveensche Plas als Waterleidingplas

Gemeentewaterleidingen Amsterdam produceert en levert drinkwater aan Amsterdam en omstreken. Het zuiveringsproces van water vindt plaats in twee produktiebedrijven, de rivierduinwaterleiding en de rivier-plassenwaterleidingen. De rivier-duinwaterleidingen krijgt het ruwe water aangeleverd door de Watertransportmaatschappij Rijn-Kennemerland (WRK...

Experimental investigations on macro cell corrosion in chloride-contaminated concrete

Chloride-induced reinforcement corrosion in concrete is characterised by the action of so-called macrocells. The associated localised form of corrosion results from the strong electrochemical interaction between the relatively small pitting sites acting as anodes and the large passive steel areas acting as cathodes. The existence of macrocell...

Kritisch chloridegehalte in gewapend beton