Using marine waste enteromorpha prolifera powder as a sustainable internal curing agent to mitigate autogenous shrinkage of UHPC

Abstract

This study uses marine waste enteromorpha prolifera powder (EPP) to mitigate the autogenous shrinkage (AS) of UHPC. The water desorption of EPP was researched first. Then the influence of EPP on the fresh properties, hydration heat, AS, mechanical strength, and microstructure of UHPC was studied. The results showed that the 28 days AS of UHPC was reduced by 25.6 % ∼ 69.4 % after adding 0.5 % ∼ 1.5 % EPP. However, the porosity of the matrix was significantly increased, resulting in 10.1 % ∼ 26.8 % and 6.6 % ∼ 19.0 % reduction for compressive strength and flexural strength of UHPC, respectively. Moreover, incorporating EPP into UHPC can improve the hydration degree of cement and increase the average chain length of C-S-H by 53.6 %. Utilizing EPP as an internal curing agent can decrease the production cost of UHPC (about 1.8 % compared with superabsorbent polymers) and offer a novel approach for the resource utilization of EPP.