Split Hopkinson pressure bar(SHPB)was used to investigate the dynamic compressive properties of sisal fiber reinforced coral aggregate concrete(SFCAC).The results showed that,with the increase of strain rate,the dynam...Split Hopkinson pressure bar(SHPB)was used to investigate the dynamic compressive properties of sisal fiber reinforced coral aggregate concrete(SFCAC).The results showed that,with the increase of strain rate,the dynamic compressive strength,peak strain and toughness index of SFCAC are all greater than its static properties,indicating that SFCAC is a kind of rate-sensitive material.When the sisal fiber was blended,the failure mode showed obvious ductility.At high strain rates,the SFCAC without sisal fiber specimen was comminuted,and the SFCAC showed a"cracked without breaking"state.The results indicated that the sisal fiber played a significant role in reinforcing and strengthening the properties of concrete.The finite element software LS-DYNA was used to simulate two working conditions with strain rates of 78 and 101 s-1.The stressstrain curves and failure patterns obtained were in good agreement with the experimental results.展开更多
In this paper,a split Hopkinson pressure bar(SHPB)was used to investigate the dynamic impact mechanical behavior of sisal fiber-reinforced cement-based composites(SFRCCs),and the microscopic damage evolution of the co...In this paper,a split Hopkinson pressure bar(SHPB)was used to investigate the dynamic impact mechanical behavior of sisal fiber-reinforced cement-based composites(SFRCCs),and the microscopic damage evolution of the composites was analyzed by scanning electron microscopy(SEM)and energy-dispersive X-ray spectrome-try(EDS).The results show that the addition of sisal fibers improves the impact resistance of cement-based composite materials.Compared with ordinary cement-based composites(OCCs),the SFRCCs demonstrate higher post-peak strength,ductility,and energy absorption capacity with higher fiber content.Moreover,the SFRCCs are strain rate sensitive materials,and their peak stress,ultimate strain,and energy integrals all increase with increasing strain rate.From the perspective of fracture failure characteristics,the failure of OCCs is dominated by the brittle failure of crystal cleavage.In contrast,the failure mode of the SFRCCs changes to microscale matrix cracks,multi-scale pull-out interface debonding of fibers(fine filaments and bundles),and mechanical interlock.This research provides an experimental basis for the engineering application of high-performance and green cement-based composites.展开更多
Based on results of previous studies,through investigations,the status quo,main advantages and disadvantages of using small hand-power scutchers and large-scale automatic sisal production lines to process sisal fiber ...Based on results of previous studies,through investigations,the status quo,main advantages and disadvantages of using small hand-power scutchers and large-scale automatic sisal production lines to process sisal fiber were summarized and analyzed; the traditional uses and latest products of sisal fiber were studied,especially the comprehensive utilization of byproducts produced during sisal fiber processing as well as the broad prospects of new sisal products.展开更多
Recently,addition of various natural fibers to high strength concrete has aroused great interest in the field of building materials.This is because natural fibers are much cheaper and locally available,as compare to s...Recently,addition of various natural fibers to high strength concrete has aroused great interest in the field of building materials.This is because natural fibers are much cheaper and locally available,as compare to synthetic fibers.Keeping in view,this current research conducted mainly focuses on the static properties of hybridized(sisal/coir),sisal and coir fiber-reinforced concrete.Two types of natural fibers sisal and coir were used in the experiment with different lengths of 10,20 and 30 mm and various natural fiber concentrations of 0.5%,1.0%,and 1.5%by mass of cement,to investigate the static properties of sisal fiber reinforced concrete(SFRC),coir fiber reinforced concrete(CFRC)and hybrid fiber reinforced concrete(HFRC).The results indicate that HFRC has increased the compressive strength up to 35.98%with the length of 20 mm and with 0.5%concentration,while the CFRC and SFRC with the length of 10 mm and with 1%concentration have increased the compressive strength up to 33.94%and 24.86%,respectively.On another hand,the split tensile strength was increased by HFRC with the length of 20 mm and with 1%concentration,CFRC with the length of 10 mm and with 1.5%concentration,and SFRC with the length of 30 mm and with 1%concentration have increased up to 25.48%,24.56%and 11.80%,respectively,while the HFRC with the length of 20 mm and with 0.5%concentration has increased the compressive strength of concrete but has decreased the split tensile strength up to 2.28%compared to PC.Overall,using the HFRC with the length of 20 mm and with 1%concentration provide the maximum output in terms of split tensile strength.展开更多
基金National Natural Science Foundation of China(Nos.51508272,11832013,51878350,52078250)。
文摘Split Hopkinson pressure bar(SHPB)was used to investigate the dynamic compressive properties of sisal fiber reinforced coral aggregate concrete(SFCAC).The results showed that,with the increase of strain rate,the dynamic compressive strength,peak strain and toughness index of SFCAC are all greater than its static properties,indicating that SFCAC is a kind of rate-sensitive material.When the sisal fiber was blended,the failure mode showed obvious ductility.At high strain rates,the SFCAC without sisal fiber specimen was comminuted,and the SFCAC showed a"cracked without breaking"state.The results indicated that the sisal fiber played a significant role in reinforcing and strengthening the properties of concrete.The finite element software LS-DYNA was used to simulate two working conditions with strain rates of 78 and 101 s-1.The stressstrain curves and failure patterns obtained were in good agreement with the experimental results.
基金supported within the framework of the Basic Research Project of the Yunnan Province-Young Program(No.2019FD097)Agricultural Joint Special Project of the Yunnan Province-General Program(No.202101BD070001-118).
文摘In this paper,a split Hopkinson pressure bar(SHPB)was used to investigate the dynamic impact mechanical behavior of sisal fiber-reinforced cement-based composites(SFRCCs),and the microscopic damage evolution of the composites was analyzed by scanning electron microscopy(SEM)and energy-dispersive X-ray spectrome-try(EDS).The results show that the addition of sisal fibers improves the impact resistance of cement-based composite materials.Compared with ordinary cement-based composites(OCCs),the SFRCCs demonstrate higher post-peak strength,ductility,and energy absorption capacity with higher fiber content.Moreover,the SFRCCs are strain rate sensitive materials,and their peak stress,ultimate strain,and energy integrals all increase with increasing strain rate.From the perspective of fracture failure characteristics,the failure of OCCs is dominated by the brittle failure of crystal cleavage.In contrast,the failure mode of the SFRCCs changes to microscale matrix cracks,multi-scale pull-out interface debonding of fibers(fine filaments and bundles),and mechanical interlock.This research provides an experimental basis for the engineering application of high-performance and green cement-based composites.
文摘Based on results of previous studies,through investigations,the status quo,main advantages and disadvantages of using small hand-power scutchers and large-scale automatic sisal production lines to process sisal fiber were summarized and analyzed; the traditional uses and latest products of sisal fiber were studied,especially the comprehensive utilization of byproducts produced during sisal fiber processing as well as the broad prospects of new sisal products.
基金This work has been supported by the Yunnan Science and Technology Major Project,Yunnan China under Grant No.202002AE090010。
文摘Recently,addition of various natural fibers to high strength concrete has aroused great interest in the field of building materials.This is because natural fibers are much cheaper and locally available,as compare to synthetic fibers.Keeping in view,this current research conducted mainly focuses on the static properties of hybridized(sisal/coir),sisal and coir fiber-reinforced concrete.Two types of natural fibers sisal and coir were used in the experiment with different lengths of 10,20 and 30 mm and various natural fiber concentrations of 0.5%,1.0%,and 1.5%by mass of cement,to investigate the static properties of sisal fiber reinforced concrete(SFRC),coir fiber reinforced concrete(CFRC)and hybrid fiber reinforced concrete(HFRC).The results indicate that HFRC has increased the compressive strength up to 35.98%with the length of 20 mm and with 0.5%concentration,while the CFRC and SFRC with the length of 10 mm and with 1%concentration have increased the compressive strength up to 33.94%and 24.86%,respectively.On another hand,the split tensile strength was increased by HFRC with the length of 20 mm and with 1%concentration,CFRC with the length of 10 mm and with 1.5%concentration,and SFRC with the length of 30 mm and with 1%concentration have increased up to 25.48%,24.56%and 11.80%,respectively,while the HFRC with the length of 20 mm and with 0.5%concentration has increased the compressive strength of concrete but has decreased the split tensile strength up to 2.28%compared to PC.Overall,using the HFRC with the length of 20 mm and with 1%concentration provide the maximum output in terms of split tensile strength.
