Study On The Properties Of HPFL Mortar For High Performance Ferrocement Reinforcement

High performance ferrocement reinforcement is a new technology which reinforces concrete and masonry structure. This technology could effectively enhance the strength, stiffness, cracking resistance, and ductility of structure. The performance of mortar of high performance ferrocement laminate (HPFL) is the key point which could fully apply to engineering. In this paper, through a large number of tests and theoretical analysis, effects of superplasticizer, polymer powders, and thickening thixotropic agent on performance of fresh mortars and compressive strength, flexural strength of hardened mortars were systematically investigated, and adhesive strengths of mortars under different curing systems were compared and then, the mixs of HPFL were optimized. The main conclusions of the study are as follows:(1) Keeping the same fluidity, by mixing superplasticizer, water-binder ratio of mortars were reduced significantly, while air content and density of mortars were increased. However, for workability of mortars, the effects of different superplasticizers were obviously different. By mixing thickening thixotropic agent, the mixture of thickening thixotropic agent improved workablity of mortars, and excellent workability of mortars could be realized by mixed manifold thickening thixotropic agents whose contents were little. However, the water-binder ratio of mortars were enhanced significantly and the air content of mortars were also increased, while the density of mortars were decreased. By mixing polymer powders, the water-binder ratio of mortars were reduced and the density of mortars were decreased, while the air content of mortars increased, and the workability of mortars were improved. The excellent workablity of mortars could be realized by mixing added superplasticizer, polymer powder, and composite thickening thixotropic agents.(2) By mixing superplasticizer, the compressive and flexural strength of mortars were increased while the toughness was reduced. By mixing thickening thixotropic agent, the flexural and compressive strength of mortars were decreased, while the toughness was enhanced. By mixing polymer powder, the flexural strength of mortars were increased slightly while the compressive strength were decreased slightly, and therefore, the toughness of mortars was improved obviously. However, the effects of different polymer powders on toughness of mortars were distinctly different.(3) The adhesive strength of mortars was significantly influenced by two curing systems in this paper. The adhesive strength of mortars was enhanced obviously by mixing superplasticizer. The mixture of thickening thixotropic agent obviously reduced adhesive strength of mortars. The adhesive strength of mortars was not increased by polymer powder, but it could reduce the influence of curing systems on adhesive strength of mortars.(4) Sand-binder ratio, kinds and particle size of sand, and stationary time of mortar specimens influenced the performance of mortars remarkably.(5) Optimizing the mix of HPFL based on experimental results, excellent workability as well as favorable mechanical properties of mortars were realized, which could be applied to high performance ferrocement reinforcement.