X-ray micro-tomographic imaging and modelling of saline ice properties in concrete frost salt scaling experiments

Frost salt scaling of concrete is related to cyclic freezing and melting of a few millimeter thick deicer solution on the surface of the concrete. It is almost absent when pure water is freezing and reaches a maximum at a so-called pessimum concentration that for NaCl is around 3%. Different mechanisms have been suggested to explain this...

Revisiting concrete frost salt scaling: On the role of the frozen salt solution micro-structure

We simulate the glue-spall stress due to mechanical interactions between a frozen saline solution (brine-ice composite) and a non-air entrained concrete surface including the impact of the micro-structure of the frozen solution. The presence of brine channels at the ice/concrete interface was found to be a prerequisite to induce stress during...

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...

Analytical calculation model for predicting cracking behavior of reinforced concrete ties

This paper formulates an analytical calculation model for predicting the cracking behavior of reinforced concrete ties to provide more consistent crack width calculation methods for large-scale concrete structures in which large bar diameters and covers are used. The calculation model was derived based on the physical behavior of reinforced...

A numerical investigation of the cracking behaviour of reinforced-concrete tie elements

The cracking behaviours of reinforced-concrete (RC) ties are investigated by conducting virtual experiments using non-linear finite-element analysis. The assumptions in the model are verified by benchmarking the classical experiments of B. Bresler and V. V. Bertero as conducted in 1968 and P. J. Yannopoulos, conducted in 1989, which shows...

Modified cracked membrane model for consistent crack width predictions of reinforced concrete structures subjected to in-plane loading

The modified cracked membrane model (MCMM) presented in this paper was formulated to facilitate a mechanical calculation model that predicts crack widths in reinforced concrete (RC) structures subjected to in-plane loading for all cracking stages. It was formulated using the basic concepts of the existing cracked membrane model (CMM)....

Experimental and theoretical investigation of crack width calculation methods for RC ties

This paper theoretically and experimentally investigates the semi-empirical formulas recommended by Eurocode 2 (EC2), fib Model Code 2010 (MC2010), and Eurocode 2 with the German National Annex (DIN) for calculating crack widths in reinforced concrete. It is shown that the formulas can be derived from the principles for the idealized behavior...

Towards an integrated simulation of casting and structural performance of flowable fibre-reinforced concrete

Most recent studies on fibre-reinforced self-compacting concrete agree on the impact of the casting conditions on the fibre orientation and distribution, and its consequence thereof on the structural performance. A substantial number of investigations are continuously contributing to gain experience on the use of flowable FRC for different...