Alkali-silica reaction: Current understanding of the reaction mechanisms and the knowledge gaps

Alkali-silica reactions (ASR): literature review on parameters influencing laboratory performance testing

Effects of carbonation on the leachability and compressive strength of cement-solidified and geopolymer-solidified synthetic metal wastes.

Electrical resistance heating for deicing and snow melting applications: Experimental study

### Concrete in the built environment

The word “concrete ” is derived from the Latin concretus (compact, condensed), representing a conjunction of con (together) and the past participle of cresco (to grow; compare: crescendo ). Thus, concrete could be liberally translated as ‘grown solid together,’ alluding to the consolidation of a particulate aggregate material with a cement binder of some sort. Concrete containing aggregate has been used in construction by the ancient Greek and Romans, possibly as a further development of clay initially used by the Assyrians and Babylonians as a binder, later superseded by burnt lime and gypsum by the Egyptians.

As a construction material, concrete allows architects and engineers to design a structure with only minimal constraints to its form. A complicated shape requiring great effort to chisel out from a piece of stone can simply be poured in a mold and reproduced as often as desired, also ex situ . Both the invention of Ordinary Portland Cement (OPC), first patented by British bricklayer Joseph Aspdin in 1824, and of reinforced concrete first patented by Parisian gardener Joseph Monier in 1867 (for making durable flower pots), contributed to the development of mechanically stronger concrete allowing yet slimmer and taller structures to be built. Today, concrete is the most popular building and construction material with an annual production volume exceeding 7.5 km3, or about 20 billion tonne. Concrete is the prime ingredient in the world’s largest and most prominent structures and landmark edifices, including hydropower dams (e.g., Three Gorges Dam, Yichang/CN; also see Charlwood and Solymar 1995), coastal defense works (e.g., Delta Works/NL), telecommunication (e.g., CN Tower, Toronto/CA), office skyscrapers (e.g., Burj Khalifa, Dubai/UAE), theatres (e.g., Opera House, Sydney/AU), hotels and casinos (e.g., Marina Bay Area, Singapore/SG), nuclear power plants, oil and gas drilling and productions rigs (e.g., Sakhalin/RU), sea ports and harbors (e.g., …

Deleterious Reactions of Aggregate With Alkalis in Concrete

Influence of acetate and formate-based deicers on ASR in airfield concrete pavements

La reactivite alcali-silice nuisant au beton est une reaction de longe duree extremement complexe. Dans le cas des granulats a reaction lente et tardive, la quantite et l'etat du quartz jouent un role determinant. Le gel de silice alcalin n'est susceptible de gonflement que dans une zone determinee de la teneur en CaO. Ainsi tous les adjuvants du ciment liant le Ca(OH) 2 forme lors de l'hydratation de C 3 S et de C 2 S, sont susceptibles d'eviter une reactivite alcali-silice nuisible au beton. Par application stricte des methode d'essai actuelles, notamment l'essai de performance, une reaction alcali-silice nuisible au beton peut etre. La partie 1 de cet article decrit les mecanismes de la reactivite alcali-silice ainsi que les avantages et inconvenients des methodes d'essai. Dans la partie 2 seront presentes en detail des approches de recherche et methodes d'essai particulieres avec les resultats ainsi que quelques cas de dommages de reactivite alcali-silice.

70 years of ASR with no end in sight? (Part 2)

Die Kombination neu entwickelter Untersuchungsverfahren (Mortelschnelltest, Klimawechsellagerung) mit gezielten Analysemethoden soll sowohl fur Gesteinskornungen als auch fur Betone eine zuverlassige Aussage zum AKRSchadigungspotential ermoglichen.

Beurteilung des AKR‐Schädigungspotentials von Betonen mittels Klimawechsellagerung

Im Rahmen des Bewerbungsverfahrens der Materialpruefungsanstalt an der Universitaet Stuttgart (MPA Universitaet Stuttgart) als zugelassener AKR-Gutachter nach Allgemeinem Rundschreiben Strassenbau (ARS) 04/2013 wurde ein breit angelegtes Untersuchungsprogramm an der MPA in Stuttgart und am Finger-Institut (FIB) in Weimar durchgefuehrt. Im ersten Teil war zunaechst anhand von Vergleichsversuchen zu beurteilen, ob bei dem an der MPA Universitaet Stuttgart vorgesehenen Einsatz der FIB-Klimawechsellagerung als AKR-Performance-Pruefung gleichlautende Aussagen bei der Beurteilung des AKR-Schaedigungspotenzials von Betonzusammensetzungen erreicht werden wie bei einer analogen Pruefung der Betonzusammensetzung am FIB in Weimar. Dazu wurden Vergleichsversuche an insgesamt vier Betonzusammensetzungen sowohl unter Einwirkung von NaCl-Loesung als auch unter Einwirkung von Wasser durchgefuehrt. Im zweiten Teil sollte an allen vier Betonzusammensetzungen die zeitliche Entwicklung der Festigkeits- und Verformungseigenschaften charakterisiert werden, um daraus Bewertungskriterien fuer AKR-Performance-Pruefungen ableiten zu koennen. (A) ABSTRACT IN ENGLISH: Within the scope of the application procedure of the Materials Testing Institute at University of Stuttgart (MPA University Stuttgart) as approved ASR consultant according to Allgemeines Rundschreiben Strassenbau (ARS) 04/2013 a comprehensive program of examinations was conducted at the MPA in Stuttgart and the Finger-Institute (FIB) in Weimar. The first part of the examinations was about to evaluate whether the ASR potential of concrete compositions is evaluated consistently at the MPA University Stuttgart and the FIB in Weimar by using the FIB cyclic climate storage test method as ASR performance test. For that purpose, a round-robin test with four different concrete compositions tested under exposure of water and NaCl solution respectively was done. The second part of the examinations was about to characterize the temporal development of the strength and deformation properties of the tested concretes to derive additional evaluation criteria for ASR performance tests. (A)

Katrin Seyfarth

Papers

Influence of acetate and formate-based deicers on ASR in airfield concrete pavements

70 years of ASR with no end in sight? (Part 2)

Beurteilung des AKR‐Schädigungspotentials von Betonen mittels Klimawechsellagerung

Festigkeits‐ und Verformungseigenschaften von Beton als Bewertungskriterien von AKR‐Performance‐Prüfungen

70 years of ASR with no end in sight? (Part 1)