The equivalent mortar volume method in the manufacturing of recycled aggregate concrete

Abstract

many studies have observed that the mechanical properties of concrete made of recycled aggregate are worse than for concrete made of natural aggregate; this is mainly due to the mortar that is attached to the recycled aggregate. In literature, an equivalent mortar volume method in the manufacturing of recycled aggregate concrete has been proposed. This method treats the attached mortar as new mortar. The application of this method can reduce the use of natural materials while maintaining mechanical properties and eliminate the additional processes required for the production of recycled aggregates. The aim of this paper is to briefly describe the recent application of this method, present gaps in current research and anticipated directions for further research.

Mineral Addition and Mixing Methods Effect on Recycled Aggregate Concrete

“…The remaining part over 4mm sieve was determined in the residual defining test after 0.1 M HCl solution attack to RA in a container. EMV requires the constant volume of aggregate as (Equation (3)) [ 21 ]:…”

“…To solve the complexity of the use of RA in new concrete safely, some researchers proposed new mixture prescriptions including mineral additions (i.e., silica fume (SF) [ 3 , 4 ], ground granulated blast furnace slag (GGBS) [ 5 , 6 ], metakaolin [ 7 ], fly ash (FA) [ 8 , 9 , 10 , 11 ], fibers with/without mineral addition (i.e., polypropylene [ 9 ], polypropylene + SF [ 12 ], steel fiber + SF [ 4 ], basalt fiber [ 13 , 14 ], basalt fiber + nano-silica [ 15 ], waste-plastic strip + FA [ 16 ], steel fiber + FA [ 17 ], steel fiber + GGBS [ 18 ], glass fiber + FA [ 19 ] or redefining mixing method (i.e., Equivalent Mortar Volume Method (EMV) [ 20 , 21 ], two stage mixing method [ 22 ]. The suggestions presented satisfactory results and gave confidence to mix designers of RAC.…”