Recycling of waste concrete has become an important issue worldwide due to the continued increase of construction wastes. Also, the growing global construction activities urge to find sustainable resources to replace natural materials for the production of concrete. In the past few decades, many researches have been carried out on the use of recycled aggregate (RA) derived from construction and demolition wastes to produce concrete products. This paper reviews the previous findings on the effects of use of RA on durability of concrete. In general, the amount of adhered mortar and the quality of the original concrete have a significant effect on the properties of resulting concrete. The increase of RA content and w/c ratio results in poorer durability of concrete. In comparison, the negative effect of recycled fine aggregate is more obvious than that of recycled coarse aggregate. The use of pozzolanic materials either for surface coating of RA or intermixed within the concrete are effective and feasible to improve the overall durability of concrete. Recent researches on CO2 treatment indicate that it can enhance the properties of RA and durability of concrete significantly.

Durability of recycled aggregate concrete – A review

This manuscript presents a review of the potential and challenge of using recycled concrete aggregate (RCA) as the substitute for natural aggregate (NA) in concrete mixtures. Using RCA in concrete preserves the environment by reducing the need for opening new aggregate quarries and decreases the amount of construction waste that goes into landfill. The properties of RCA such as specific gravity, absorption, and the amount of contaminant present in it contribute to the strength and durability of concrete. The quality of RCA depends on the features of the original aggregate and the condition of the demolished concrete. Some researchers have reported that the use of RCA degrades concrete properties while others have successfully produced RCA concrete with a performance that matched normal concrete (NC). In addition to the influence of RCA to concrete properties, this paper also evaluates multiple techniques to improve the performance of RCA concrete, reported cost savings in concrete production and recommendations regarding the application of RCA in concrete.

Properties of recycled concrete aggregate and their influence in new concrete production

Fresh properties of a novel 3D printing concrete ink

https://orbi.uliege.be/bitstream/2268/199324/1/Article%20of%20CBM.pdf

Influence of fine recycled concrete aggregates on the properties of mortars

Rheological and harden properties of the high-thixotropy 3D printing concrete

Use of calcium sulfoaluminate cements for setting control of 3D-printing mortars

https://www.tpbin.com/Uploads/Subjects/ff243e0f-456e-4371-8d72-7b38cb553912.pdf

Influence of cement grouts composition on the rheological behaviour

A linear relationship was found between the mean size of four granular classes (0/0.63, 0.63/1.25, 1.25/2.5, 2.5/5 mm) of different laboratory-made fine recycled concrete aggregates (FRCA) and their hardened cement paste content (CPC). A method based on salicylic acid dissolution was specifically developed for the measurement of CPC. Results showed that bound water and density of FRCA were strongly correlated with their CPC. Identically, the water absorption coefficient also followed a linear trend as a function of the CPC but only for the three coarser granular classes. Indeed, the water absorption coefficient of the finer fraction of FRCA (0/0.63 mm) cannot be correctly measured using European standard method EN 1097-6 or method no. 78 of IFSTTAR; but it can be obtained by extrapolation from the previous linear trend. As a consequence, the accurate total water absorption of FRCA (fraction 0/5 mm) can be estimated.

/pdf/influence-of-hardened-cement-paste-content-on-the-water-vm8lo68179.pdf

Sébastien Remond

Papers

Influence of fine recycled concrete aggregates on the properties of mortars

Use of calcium sulfoaluminate cements for setting control of 3D-printing mortars

Influence of cement grouts composition on the rheological behaviour

Influence of hardened cement paste content on the water absorption of fine recycled concrete aggregates

A DEM hard-core soft-shell model for the simulation of concrete flow