网格增强UHPC薄板拉伸力学性能试验研究
|
摘要
为进一步提升超高性能混凝土(UHPC)薄壁结构的可施工性、拉伸强度及延性,针对网格增强UHPC薄板开展拉伸力学性能研究.选取了4种市售成品网格,使用1%钢纤维掺量UHPC,制备了网格增强UHPC薄板.通过单轴拉伸试验,研究了不同网格类型、网格处理方式、网格层数对网格增强UHPC薄板试件力学性能及裂缝形态的影响.结果表明:碳纤维网格对UHPC增强效果显著,但其性能发挥依赖网格与UHPC基体的黏结,因而网格经环氧树脂胶浸渍并于表面粘砂是保证黏结的有效途径;不锈钢网格与UHPC基体黏结良好,能提高试件的开裂荷载和峰值荷载,且网格层数的增多,能增加裂缝数量,并大幅提升试件延性;碳-玻璃纤维混编网格由于易发生胶层过早脱黏而导致其不能与UHPC基体建立良好黏结,增强效果不理想;玄武岩网格受限于网格自身承载力不足,增强效果不明显.
To improve the workability, tensile strength and ductility of ultra-high performance concrete(UHPC) thin-walled structure, the tensile mechanical property of gird reinforced UHPC plates is studied. Four kinds of girds available in the market were used to fabricate the grids reinforced UHPC plates, combined with ultra-high performance concrete with steel fibers of 1% volume fraction. The effects of different gird types, gird processing methods and number of gird layers on the mechanical property and cracking patterns of grids reinforced UHPC plates were investigated by uniaxial tensile tests. The results indicate that carbon fiber girds have a remarkable reinforcing effect on UHPC. However, the performance of carbon fiber grids reinforced UHPC depends on the bonding conditions between grids and UHPC matrix. Epoxy resin impregnation and sand covering are effective ways to ensure satisfied bonding conditions.The bonding conditions between stainless steel grids and UHPC matrix are good enough, which makes the cracking load and peak load of the specimens increase. Meanwhile, the number of cracks increases and the ductility of specimens improves significantly, with the increase of the number of grid layers.The reinforcing effect of carbon-glass fiber hybrid grids is unsatisfied due to poor bonding conditions of the grids and UHPC matrix caused by the premature debonding of the adhesive layer. Due to the limited bearing capacity of the basalt grid itself, the reinforcing effect of basalt girds is not obvious.
To improve the workability, tensile strength and ductility of ultra-high performance concrete(UHPC) thin-walled structure, the tensile mechanical property of gird reinforced UHPC plates is studied. Four kinds of girds available in the market were used to fabricate the grids reinforced UHPC plates, combined with ultra-high performance concrete with steel fibers of 1% volume fraction. The effects of different gird types, gird processing methods and number of gird layers on the mechanical property and cracking patterns of grids reinforced UHPC plates were investigated by uniaxial tensile tests. The results indicate that carbon fiber girds have a remarkable reinforcing effect on UHPC. However, the performance of carbon fiber grids reinforced UHPC depends on the bonding conditions between grids and UHPC matrix. Epoxy resin impregnation and sand covering are effective ways to ensure satisfied bonding conditions.The bonding conditions between stainless steel grids and UHPC matrix are good enough, which makes the cracking load and peak load of the specimens increase. Meanwhile, the number of cracks increases and the ductility of specimens improves significantly, with the increase of the number of grid layers.The reinforcing effect of carbon-glass fiber hybrid grids is unsatisfied due to poor bonding conditions of the grids and UHPC matrix caused by the premature debonding of the adhesive layer. Due to the limited bearing capacity of the basalt grid itself, the reinforcing effect of basalt girds is not obvious.
引文
[1] Classen M,Gallwoszus J,Stark A.Anchorage of composite dowels in UHPC under fatigue loading[J].Structural Concrete,2016,17(2):183-193.DOI:10.1002/suco.201500034.
[2] Zhang F R,Wu C Q,Zhao X L,et al.Experimental study of CFDST columns infilled with UHPC under close-range blast loading[J].International Journal of Impact Engineering,2016,93:184-195.DOI:10.1016/j.ijimpeng.2016.01.011.
[3] Alkaysi M,El-Tawil S,Liu Z C,et al.Effects of silica powder and cement type on durability of ultra high performance concrete (UHPC)[J].Cement and Concrete Composites,2016,66:47-56.DOI:10.1016/j.cemconcomp.2015.11.005.
[4] Richard P.Reactive powder concretes with high ductility and 200-800 MPa compressive strength[J].ACI Spring Conversion,1994,114:507-518.
[5] Yu R,Spiesz P,Brouwers H J H.Development of an eco-friendly ultra-high performance concrete (UHPC) with efficient cement and mineral admixtures uses[J].Cement and Concrete Composites,2015,55:383-394.DOI:10.1016/j.cemconcomp.2014.09.024.
[6] Alkaysi M,El-Tawil S.Effects of variations in the mix constituents of ultra high performance concrete (UHPC) on cost and performance[J].Materials and Structures,2016,49(10):4185-4200.DOI:10.1617/s11527-015-0780-6.
[7] Lin Y Z,Yan J C,Wang Z F,et al.Effect of silica fumes on fluidity of UHPC:Experiments,influence mechanism and evaluation methods[J].Construction and Building Materials,2019,210:451-460.DOI:10.1016/j.conbuildmat.2019.03.162.
[8] Lopez J A,Serna P,Camacho E,et al.First ultra-high-performance fibre-reinforced concrete footbridge in spain:Design and construction[J].Structural Engineering International,2014,24(1):101-104.DOI:10.2749/101686614x13830788505793.
[9] A?tcin P C,Lachemi M,Adeline R,et al.The sherbrooke reactive powder concrete footbridge[J].Structural Engineering International,1998,8(2):140-144.DOI:10.2749/101686698780489243.
[10] Williams Portal N,Nyholm Thrane L,Lundgren K.Flexural behaviour of textile reinforced concrete composites:Experimental and numerical evaluation[J].Materials and Structures,2017,50:4.DOI:10.1617/s11527-016-0882-9.
[11] Contamine R,Si Larbi A,Hamelin P.Contribution to direct tensile testing of textile reinforced concrete (TRC) composites[J].Materials Science and Engineering:A,2011,528(29/30):8589-8598.DOI:10.1016/j.msea.2011.08.009.
[12] Du Y X,Zhang M M,Zhou F,et al.Experimental study on basalt textile reinforced concrete under uniaxial tensile loading[J].Construction and Building Materials,2017,138:88-100.DOI:10.1016/j.conbuildmat.2017.01.083.
[13] Yang S L,Millard S G,Soutsos M N,et al.Influence of aggregate and curing regime on the mechanical properties of ultra-high performance fibre reinforced concrete (UHPFRC)[J].Construction and Building Materials,2009,23(6):2291-2298.DOI:10.1016/j.conbuildmat.2008.11.012.
[14] Hegger J,Will N,Bruckermann O,et al.Load-bearing behaviour and simulation of textile reinforced concrete[J].Materials and Structures,2006,39(8):765-776.DOI:10.1617/s11527-005-9039-y.
[15] Banholzer B,Brockmann T,Brameshuber W.Material and bonding characteristics for dimensioning and modelling of textile reinforced concrete (TRC) elements[J].Materials and Structures,2006,39(8):749-763.DOI:10.1617/s11527-006-9140-x.
[16] 徐世烺,阎轶群.低配网率纤维编织网增强混凝土轴拉力学性能[J].复合材料学报,2011,28(5):206-213.DOI:10.13801/j.cnki.fhclxb.2011.05.007.Xu S L,Yan Y Q.Mechanical properties of textile reinforced concrete plate at low textile ratios[J].Acta Materiae Compositae Sinica,2011,28(5):206-213.DOI:10.13801/j.cnki.fhclxb.2011.05.007.(in Chinese)
[2] Zhang F R,Wu C Q,Zhao X L,et al.Experimental study of CFDST columns infilled with UHPC under close-range blast loading[J].International Journal of Impact Engineering,2016,93:184-195.DOI:10.1016/j.ijimpeng.2016.01.011.
[3] Alkaysi M,El-Tawil S,Liu Z C,et al.Effects of silica powder and cement type on durability of ultra high performance concrete (UHPC)[J].Cement and Concrete Composites,2016,66:47-56.DOI:10.1016/j.cemconcomp.2015.11.005.
[4] Richard P.Reactive powder concretes with high ductility and 200-800 MPa compressive strength[J].ACI Spring Conversion,1994,114:507-518.
[5] Yu R,Spiesz P,Brouwers H J H.Development of an eco-friendly ultra-high performance concrete (UHPC) with efficient cement and mineral admixtures uses[J].Cement and Concrete Composites,2015,55:383-394.DOI:10.1016/j.cemconcomp.2014.09.024.
[6] Alkaysi M,El-Tawil S.Effects of variations in the mix constituents of ultra high performance concrete (UHPC) on cost and performance[J].Materials and Structures,2016,49(10):4185-4200.DOI:10.1617/s11527-015-0780-6.
[7] Lin Y Z,Yan J C,Wang Z F,et al.Effect of silica fumes on fluidity of UHPC:Experiments,influence mechanism and evaluation methods[J].Construction and Building Materials,2019,210:451-460.DOI:10.1016/j.conbuildmat.2019.03.162.
[8] Lopez J A,Serna P,Camacho E,et al.First ultra-high-performance fibre-reinforced concrete footbridge in spain:Design and construction[J].Structural Engineering International,2014,24(1):101-104.DOI:10.2749/101686614x13830788505793.
[9] A?tcin P C,Lachemi M,Adeline R,et al.The sherbrooke reactive powder concrete footbridge[J].Structural Engineering International,1998,8(2):140-144.DOI:10.2749/101686698780489243.
[10] Williams Portal N,Nyholm Thrane L,Lundgren K.Flexural behaviour of textile reinforced concrete composites:Experimental and numerical evaluation[J].Materials and Structures,2017,50:4.DOI:10.1617/s11527-016-0882-9.
[11] Contamine R,Si Larbi A,Hamelin P.Contribution to direct tensile testing of textile reinforced concrete (TRC) composites[J].Materials Science and Engineering:A,2011,528(29/30):8589-8598.DOI:10.1016/j.msea.2011.08.009.
[12] Du Y X,Zhang M M,Zhou F,et al.Experimental study on basalt textile reinforced concrete under uniaxial tensile loading[J].Construction and Building Materials,2017,138:88-100.DOI:10.1016/j.conbuildmat.2017.01.083.
[13] Yang S L,Millard S G,Soutsos M N,et al.Influence of aggregate and curing regime on the mechanical properties of ultra-high performance fibre reinforced concrete (UHPFRC)[J].Construction and Building Materials,2009,23(6):2291-2298.DOI:10.1016/j.conbuildmat.2008.11.012.
[14] Hegger J,Will N,Bruckermann O,et al.Load-bearing behaviour and simulation of textile reinforced concrete[J].Materials and Structures,2006,39(8):765-776.DOI:10.1617/s11527-005-9039-y.
[15] Banholzer B,Brockmann T,Brameshuber W.Material and bonding characteristics for dimensioning and modelling of textile reinforced concrete (TRC) elements[J].Materials and Structures,2006,39(8):749-763.DOI:10.1617/s11527-006-9140-x.
[16] 徐世烺,阎轶群.低配网率纤维编织网增强混凝土轴拉力学性能[J].复合材料学报,2011,28(5):206-213.DOI:10.13801/j.cnki.fhclxb.2011.05.007.Xu S L,Yan Y Q.Mechanical properties of textile reinforced concrete plate at low textile ratios[J].Acta Materiae Compositae Sinica,2011,28(5):206-213.DOI:10.13801/j.cnki.fhclxb.2011.05.007.(in Chinese)