Study on the mechanical properties of lightweight engineered geopolymer composite prepared by recycled concrete powder
SUN Liucun
YU Long
LIU Bin
Abstract：This paper developed a lightweight engineered geopolymer composite(LWEGC),which was synthesized by using re-cycled concrete powder(RCP)to replace metakaolin and silica fume as the precursors,fly ash cenosphere as the lightweight aggre-gate,and polyethylene fiber as reinforcement,under the activation of anhydrous sodium metasilicate and waterglass.The results showed that the replacement of RCP with no more than 50%doping,even if the particle size increased to 100 mesh,can still achieve ideal mechanical properties.The density was kept in the range of 1100～1200 kg/m3,the compressive strength was up to 20 MPa,the tensile strength was more than 2.5 MPa,and the tensile strain was more than 4.5%.The extremely-low 0.7%fiber content was sufficient for the current geopolymer system to produce excellent tensile strain-hardening property.The replacement of RCP weakened the fiber-matrix interfacial bonding,thereby compromising the mechanical strength,but promoting the multi-cracking ability.The replacement of RCP changed the type of geopolymerization product,forming calcium silica-aluminate hydrate(C-A-S-H)gels.
Keywords：recycled concrete powderlightweightengineered geopolymer compositepolyethylene fibermechanical properties
Publication Date：2025-03-25
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：6( 36-41 )