Elastic Lateral Features of a New Glass Fiber Reinforced Gypsum Wall

Transcription

1 Vol:, No:3, Elastc Lateral Features of a New Glass Fber Renforced Gypsum Wall Zhengyong Lu, Huqng Yng Internatonal Scence Index, Cvl and Envronmental Engneerng Vol:, No:3, waset.org/publcaton/67 Abstract GFRG(Glass Fber Renforced Gypsum) wall s a green product whch can erect a buldng fast n prefabrcated method, but ts applcaton to hgh-rse resdental buldngs s lmted for ts poor lateral stffness. Ths paper has proposed a modfcaton to GFRG walls structure to ncrease ts lateral stffness, whch amng to erect small hgh-rse resdental buldngs as load-bearng walls. The elastc fnte element analyss to t has shown the lateral deformaton feature and the dstrbutons of the axal force and the shear force. The analyss results show that the new GFRG renforced concrete wall can be used for small hgh-rse resdental buldngs. Keywords GFRG wall; lateral features; elastc analyss; resdental buldng. I. INTRODUCTION OUSING ndustralzaton promoton n Chna has lghted H the researchers eagerness of fndng new ways to erect resdental buldngs n prefabrcaton method. The mult-rbbed composte wall [] put forward by X an Unversty are supposed to be used n small hgh-rse housng buldngs. The research on the dense rb grd beat shearng force rapd-wall [3] (put forward by Guzhou Unversty) shows that t has enough lateral stffness and s possble to be used n small hgh-rse resdental buldngs. Glass fber renforced gypsum (GFRG) wall s a green product whch can erect a buldng fast n prefabrcated method. Appeared frst n Australa n early 99s, substantal research and practces on GFRG walls have been carred n Australa and a few Asan countres such as Chna, Malaysa and Inda. GFRG walls can be used n low buldngs as load-bearng walls and n low-rse buldngs or as upper storey walls n hgh-rse buldng when flled wth concrete n the hollow cores. The applcaton of GFRG wall s lmted for ts poor lateral stffness even though t s flled concrete n ts hollow cores. Fndng a new way to enhance ths dsadvantage (ts lateral stffness) to make t sutable for small hgh-rse resdental buldng s a valuable choce for researchers. Z.Y. Lu s wth the Buldng department of Cvl engneer college, Tong Unversty, Shangha 9, Chna, tel: ; fax: (e-mal: fcyygsl@63.com). H.Q. Yng s wth the Buldng department of Cvl engneer college, Tong Unversty, Shangha 9, Chna, tel: ; fax: (e-mal: tuyhq@63.com). II. MODIFYING GFRG Whlst GFRG wall have lmted applcaton as load-bearng member, modfcaton on t may be adapted for a wde range of mult-storey offces, small hgh-rse resdences and schools etc. To fulfll the demand, Modfcaton to the GFRG wall s structure should be focus on how to ncrease ts lateral stffness so that t deforms small when bearng the lateral loads. Consdered the GFRG wall s structure and ts manufacture, ths paper has proposed some adapted to t to ncrease ts lateral stffness. The frst s to enlarge the GFRG wall s hollow cores ensure that the renforcement cage can be hung n and then fll concrete n-stu to form the renforced concrete dense columns. The second s to heghten the beam n order to keep the wall work together. The thrd s to form the large sze end columns. Fg. shows the detals of GFRG walls flled wth concrete (a) and Modfyng GFRGM-GFRG renforced concrete walls (b). Floor s cast n stu wth deep beam and dense columns and end columns together. The GFRG panels works as the form of M-GFRG walls. Deep beam has enough stffness to keep the columns work as one. Dense columns and end columns are renforced concrete members. GFRG Form can be gnored when M-GFRG renforced concrete walls are bearng lateral loads. III. STRUCTURE ADVANTAGES OF M-GFRG In buldng constructon, The M-GFRG are transported to the constructon ste and erected n a smlar way to the constructon of precast concrete panels. The renforcement cages are bounded before hangng n the hollow core, and then cast concrete to form dense columns and end columns. Ths constructon technology saves lots of materals and tme. Snce the floor and the renforced concrete walls are cast n-stu together, ths structure system of concrete-n-stu s monolthc. Monolthc structures are good n terms of strength, rgd, ductlty and energy dsspaton, and they have good expresson durng wnd and sesmc acton, so the buldng erectng wth M-GFRG walls have good prospects n small hgh-rse resdental buldng. The bond nterfaces between the concrete and the GFRG panel s relatvely weak, and the GFRG panel s stffness s far smaller than the concrete columns, therefore the GFRG panel can be gnored when analyzng and desgnng. Internatonal Scholarly and Scentfc Research & Innovaton (3) 7 scholar.waset.org/37-689/67

2 Vol:, No:3, connectng beam dense rb g rd deep beam en d colum n steel bar dense colum n steel bar GFRG Form GFRG Form nfll co ncrete Longtudnal renforcem ent n fll concrete renforcem ent cage Internatonal Scence Index, Cvl and Envronmental Engneerng Vol:, No:3, waset.org/publcaton/67 - (a) Fg. GFRG wall flled wth concrete (a) and M-GFRG renforced concrete wall (b) IV. 3-D FINITE ELEMENT MODEL Analyss of M-GFRG renforced concrete wall was performed to study the lateral deformaton feature and the nternal force dstrbuton of M-GFRG wall when bearng lateral loads under normal condton. A small hgh-rse resdental buldng s often 8to stores, 8tom heght. The models created are stores, 3.9m. floors h3 h h h kn kn c b c c c c a b b b b b x c c c b b b c b c a Fg. The schematc dagram of 3-D FEM model (X-dstance of the column centers to the model center) The numercal analyses ddn t deal wth the lmt strength of the M-GFRG wall, whch related to the lateral deformaton feature under normal condton, therefore t was analyzed usng FEM program n elastc stage. B - (b) Snce the functon of GFRG panels can be gnored when bearng loads, renforced concrete fnte element of M-GFRG renforced concrete walls were modeled only. Fve three-dmensonal fnte element models were created. Those models consst of four M-GFRG renforced concrete walls and one renforcng concrete shear wall. Fg and Table are the FEM models and ther parameters values. The frst consderaton to models s the comparson of the M-GFRG renforced concrete walls to the renforced concrete shear wall, tryng to study the rato of the M-GFRG renforced concrete walls stffness to sold renforced concrete wall s stffness. The second consderaton s the affecton of the sze of deep beam to the lateral feature. The thrd s the affecton of the sze of end columns to the lateral feature. TABLE I VALUE OF PARAMETERS OF MODELS (MM) a b c h h h3 6 6 M M Renforcng concrete shear wall (sold) B H=63 39, total floors, t (thck) =. V. NUMERICAL RESULTS A. The lateral-dsplacement feature The lateral-dsplacement curves from the FEM analyses are shown n Fg.3. Table lsts the dates for more clarty. The results show that the nter-story drfts of M-GFRG ncreate on the lower stores but reverse on the hgher stores, whch means ts lateral-dsplacement feature s shear-flexural Internatonal Scholarly and Scentfc Research & Innovaton (3) 76 scholar.waset.org/37-689/67

3 Vol:, No:3, type, comprson to that of renforcng concrete shear wall (M), whch s flexural type. The max nter-story drft occurred at the 7th floor, ust the half heght of the walls. The top dsplacement of the M s the smallest of the four M-GFRG models. Its heght of deep beam (mm) s larger than that of (mm) and lesser than that of (mm). Ths shows that the M-GFRG lateral stffness vares wth the rato of deep beam stffness to dense column stffness. A sutable rato of deep beam stffness to dense column stffness can make M-GRFG more rgd. 3 3 d spl acement ( mm) He ght ( m) Fg. 3 Lateral-dsplacement curves (Left to rght: M, M,,, ) Internatonal Scence Index, Cvl and Envronmental Engneerng Vol:, No:3, waset.org/publcaton/67 M M TABLE II DATES OF THE INTER-STORY DRIFT AND TOTAL DISPLACEMENT ( MM) Floor number I-story drft total dsp I-story drft total dsp I-story drft total dsp I-story drft total dsp I-story drft total dsp The top dsplacement of the M-GFRG wall models vared from 7.67mm to 6.3mm. The ratos of top dsplacement to wall heght are. to.8. The largest nter-story drft of the M-GFRG wall vared from.7mm to.8mm. The ratos of the largest nter-story drft to story heght are. to., whch s far lower than the Chna code lmt (.). The results show that the lateral stffness of M s smaller than that of M Its top total dsplacement s.7 tmes that of M, whle the top total dsplacement of (the most flexble) s.8 tmes that of M. Snce M s renforcng concrete shear wall, whose strength and stffness are enough for hgh-rse buldng, M-GFRG s possble to be used for small hgh-rse resdental. B. Axal force(a-f) dstrbuton of columns Fg.. shows the axal force dstrbuton of dense columns and end columns at the mddle layer secton of the frst story (a) and the second story (b). Results show that the relatonshp between the axal forces of the dense columns and the dstances of the dense column centers to M-GFRG secton center (x ) s smlarly lnear, whch doesn t change wth the secton elevaton. The relatonshp between the axal force of the end columns and x goes beyond the lnear, for the reason that ther secton areas are larger than the dense columns A- F( kn) (a-elevaton: +.77m) M (b-elevaton: +.7m) Fg. Axal force dstrbuton of columns Results also lght that the axal forces of the columns have A- F( kn) M Internatonal Scholarly and Scentfc Research & Innovaton (3) 77 scholar.waset.org/37-689/67

4 Vol:, No:3, Internatonal Scence Index, Cvl and Envronmental Engneerng Vol:, No:3, waset.org/publcaton/67 lttle relaton to the sze of the deep beam, but the column secton areas can change the curve. We can easly get the calculaton formula of the axal forces from the curves: AG M x I f N = + n n+ A I x = = G the structural dead weght A the wall secton area of the th column I the secton lateral nerta moment I f the addtonal secton lateral nerta moment M the secton moment. C. Horzontal shear force(s-f) dstrbuton of columns Fg. shows the horzontal shear stress of the columns of dfferent secton elevaton (elevaton: +.77m to +3.m). Fg. (a) comes from the mddle layer secton of the frst story of the M-GFRG walls, ther horzontal shear force of dense columns vared smlarly to a lne. The curves show that the shear force s nearly dstrbuted by the columns stffness at the wall bottom story. Ths varaton pattern s largely decded by the fxng bottom. The horzontal shear force of end columns vared n dfferent way, the reason of whch s ther larger secton areas. 3 M (a-elevaton: +.77m) M (b-elevaton: +.7m) M (c-elevaton: +7.67m) M (d-elevaton: +.6m) M (e-elevaton: +3.7m) M (f-elevaton: +6.m) M (g-elevaton: +9.7m) M (h-elevaton: +.m) Internatonal Scholarly and Scentfc Research & Innovaton (3) 78 scholar.waset.org/37-689/67

5 Vol:, No:3, Internatonal Scence Index, Cvl and Envronmental Engneerng Vol:, No:3, waset.org/publcaton/ M (- elevaton: +.37m) (- 8 M (-elevaton: +8.3m) 6 3 M (k-elevaton: +3.7m) M (l-elevaton: +3.m) Fg. the horzontal shear force dstrbuton of columns Fg. (b)~(l) come from the other stores, ther horzontal shear force of dense columns vared smlarly to a quadratc curve whch means that the dstrbuton of the shear force s lnear relaton to x whch s totally dfferent from that of the bottom story. Take the ant-shear strength of the M-GFRG walls nto consderaton; the most mportant secton s the mddle layer secton of the bottom story for structure nner force calculaton and desgn. The axal forces calculaton formula of the bottom story secton can be formulated as follow: VI V = α n I I the th column nerta moment α the shear effect coeffcent V the th column shear force VI. SUMMARY AND CONCLUSION Ths paper presented a new GFRG wall, named M-GFRG wall, whch ntended to erect small hgh-rse resdental. Consderatons on M-GFRG walls show that they can erect buldng fast lke GFRG wall n prefabrcated method. The followng conclusons of ts lateral deformaton feature are derved from the elastc FEM analyss. A. The lateral stffness of M-GFRG wall s a lttle smaller than that of renforcng concrete shear wall, but t stll s enough rgd for the small hgh-rse buldng. B. The nter-story drfts of M-GFRG ncreate at the lower stores but reverse at the hgher stores; ts lateral-dsplacement feature s shear-flexural type. The largest nter-story drft occurred at the half heght of walls. C. The relatonshp between the axal forces and the dstances of the dense column centers to M-GFRG secton center (x) s smlarly lnear. D. The horzontal shear force dstrbuton of dense columns s dfferent from the bottom story to the hgher stores. The bottom shear force s dstrbuted by the columns stffness. Ths varaton pattern s largely affected by the fxng bottom. The shear force of the hgher stores are dstrbuted by the dstances to the wall center (x) whch smlar to the sold secton wall. The elastc analyss shows that the M-GFRG wall s possble to be used n the small hgh-rse resdental. But t stll needs more theory analyss and experment research for engneer applcaton. REFERENCES [] Yu-Fe Wu, The effect of longtudnal renforcement on the cyclc shear behavor of glass fber renforced gypsum wall panels: tests Engneerng Structures 6 () [] Chen Png, Zhao Dong, Yao Qanfeng. A study on the bearng capacty of the Mult-rbbed composte wall. Journal of X an unversty of Arch and Tech. vol.3 No. 6-9 [3] HUAN G Shou yun, Two Knds of New Envronmental Protecton Walls of Shapng of Gypsum-the Structure and Mechancs Characterstc of the Rapd-wall are Compared, Journal Of Guzhou Unversty of Technology, Chna, 6.8 [] Kang Lu, Yu-Fe Wu, Xn-Lang Jang, Shear strength of concrete flled glass fber renforced gypsum walls, Materals and Structures, AUS, 7 [] LU X-ln, JIN Guofang, WU Xaohan, theory and applcaton of nonlnear fnte element of renforced concrete [M], Shangha: Tong Unversty Press, 997 [6] Wu YF, Dare MP () Axal and shear behavor of glass fber renforced gypsum wall panels: test. J Compos Constr ASCE 8(6): Internatonal Scholarly and Scentfc Research & Innovaton (3) 79 scholar.waset.org/37-689/67

6 Vol:, No:3, [7] R. J. Vdmar. (99, August). On the use of atmospherc plasmas as electromagnetc reflectors. IEEE Trans. Plasma Sc. [Onlne]. (3). pp Avalable: http: // ps3 Internatonal Scence Index, Cvl and Envronmental Engneerng Vol:, No:3, waset.org/publcaton/67 Internatonal Scholarly and Scentfc Research & Innovaton (3) 8 scholar.waset.org/37-689/67