高溫后型鋼混凝土T形柱力學(xué)性能的試驗(yàn)研究
發(fā)布時(shí)間：2018-07-21 19:18
【摘要】：型鋼混凝土異形柱結(jié)構(gòu)是把鋼骨架埋入鋼筋混凝土中的一種新型結(jié)構(gòu)形式,因其具有良好的布置靈活性和優(yōu)于普通混凝土柱的承載力及抗震性能,被廣泛的運(yùn)用于高層建筑中。隨著高層建筑在現(xiàn)代建筑中占據(jù)越來(lái)越重要的地位,高層建筑的結(jié)構(gòu)安全受到廣泛的關(guān)注,各種災(zāi)害中火災(zāi)對(duì)建筑物的危害尤為嚴(yán)重。由于型鋼柱的含鋼率較高、受火面積大,因此高溫下其承載力損失程度和危險(xiǎn)程度也要高于普通混凝土柱,為了保護(hù)人身安和減少經(jīng)濟(jì)損失,同時(shí)也為了給火災(zāi)救援及后期修復(fù)工作提供一定的理論依據(jù),有必要對(duì)異形柱火災(zāi)后的力學(xué)性能進(jìn)行進(jìn)一步研究。本文主要研究了型鋼混凝土T形柱高溫后的力學(xué)性能,主要工作及結(jié)論如下:本文設(shè)計(jì)了11根T形SRC柱,利用自制電加熱爐進(jìn)行了恒溫條件下的四面受火試驗(yàn),對(duì)高溫后試件在不同設(shè)計(jì)變量和加載條件下(水平腹桿間距、含鋼率、加載角、偏心距)進(jìn)行力學(xué)試驗(yàn)研究,將相關(guān)數(shù)據(jù)進(jìn)行了整理與分析,得到如下結(jié)論:(1)高溫作用后,異形柱受高溫區(qū)混凝土表面顏色變?yōu)榛野咨?隨恒溫時(shí)間增加,局部呈現(xiàn)淡紅色。柱子背部中間區(qū)段內(nèi)出現(xiàn)細(xì)微裂縫,部分試件表面有粉狀物質(zhì)析出。各試件相同測(cè)點(diǎn)處升溫趨勢(shì)基本一致,越靠近T形柱表面的測(cè)點(diǎn)溫度升高的越快。恒溫時(shí)間3小時(shí)的各試件,截面溫度場(chǎng)變化規(guī)律基本一致,理論上可以認(rèn)為各試件經(jīng)歷相同高溫時(shí)長(zhǎng)后的損傷相同。600℃下恒溫1h、2h和3h后,試件自由膨脹率分別為0.47%、0.67%和0.75%,各試件軸向變形量隨恒溫時(shí)長(zhǎng)增加呈現(xiàn)線性增長(zhǎng)規(guī)律。腹桿間距對(duì)試件最終的軸向變形量基本沒(méi)有影響,試件最終的軸向變形量隨含鋼量增加而減小。(2)高溫后軸心受壓T形柱在荷載作用下的破壞過(guò)程和破壞形態(tài)與常溫下試件基本相同。偏心受壓構(gòu)件破壞形態(tài)與軸壓試件類似,但偏心受壓試件初裂荷載和剝落荷載均有大幅度提前,最終的破壞形態(tài)表現(xiàn)為偏心受壓一側(cè)混凝土嚴(yán)重剝落,受壓側(cè)型鋼屈服外露,另一側(cè)出現(xiàn)水平貫通裂縫。常溫下試件在破壞時(shí),柱身裂縫明顯少于經(jīng)歷過(guò)高溫的試件,并且試件也維持了較好的完整性;經(jīng)歷過(guò)高溫的試件在破壞時(shí),柱身都產(chǎn)生了大量的裂縫,且主裂縫較寬,柱身破壞嚴(yán)重,變形也更嚴(yán)重。(3)常溫下對(duì)比試件軸向剛度要明顯大于受高溫后的試件。受高溫后的試件在相同荷載下的軸向變形明顯大于常溫下對(duì)比試件,剛度退化速度也更快。恒溫60min、120min和180min的試件較常溫對(duì)比試件的強(qiáng)度衰減率分別為16.1%、19.3%和24.8%;沿X軸加載,加載偏心距分別為40mm和80mm試件強(qiáng)度較軸心加載的試件分別降低了9%和14.1%;偏心受壓試件在最終破壞時(shí)的極限變形量隨偏心距的增大而明顯增大,大體呈現(xiàn)線性趨勢(shì)。腹桿間距對(duì)高溫后軸壓試件的前期剛度影響不大,加載中期腹桿間距為200mm的試件T-04軸壓剛度要明顯優(yōu)于腹桿間距為300mm和400mm的試件,極限承載力隨水平腹桿間距變化無(wú)明顯變化規(guī)律;高溫后試件含鋼率增加15%,破壞時(shí)的殘余承載力增加了24%;不同加載角對(duì)高溫后試件豎向變形-荷載曲線的前期影響較小,但當(dāng)各試件臨近極限荷載時(shí),加載角為45°的試件豎向變形量明顯大于加載角為0°和90°的試件。
[Abstract]:Profiled steel concrete special-shaped column is a new type of structural form of steel frame embedded in reinforced concrete. It is widely used in high rise buildings because of its good flexibility in layout and superior to the bearing capacity and seismic performance of ordinary concrete columns. With high rise building, it occupies a more and more important position in the present generation. The structure safety of the building is widely concerned. The damage of fire to the building is particularly serious in all kinds of disasters. Because of the high steel ratio and large area of fire, the bearing capacity loss and risk degree of the steel column are higher than that of the ordinary concrete column at high temperature. The disaster relief and later repair work provide a certain theoretical basis. It is necessary to further study the mechanical properties of the special-shaped columns after fire. This paper mainly studies the mechanical properties of the steel concrete T shaped columns after high temperature. The main work and conclusions are as follows: 11 T shaped SRC columns are designed in this paper, and the constant temperature conditions are carried out by the self-made electric heating furnace. Under the fire test of four sides, the mechanical tests were carried out on the specimens under different design variables and loading conditions (horizontal bar spacing, steel ratio, loading angle, eccentricity). The related data were arranged and analyzed. The following conclusions were obtained: (1) after the high temperature action, the surface of the special shaped column changed to gray white with the color of the concrete surface in the high temperature area. In the middle section of the back of the column, there are fine cracks in the middle section of the back of the column, and the surface of the part of the specimen has a powder substance. The temperature of the test points near the surface of the T column is higher. The temperature field of the cross section is basically the same in the 3 hours at constant temperature. In theory, it is believed that the free expansion rate of the specimen is 0.47%, 0.67% and 0.75% respectively after the same high temperature of 1H, 2h and 3H at the same temperature at the same high temperature at.600 C. The axial deformation of each specimen increases linearly with the increase of the constant temperature. The axial deformation amount decreases with the increase of steel content. (2) the failure process and failure mode of the axial compression T column under the load are basically the same as those under the normal temperature. The failure mode of the eccentric compression member is similar to that of the axial compression specimen, but the initial and the exfoliation loads of the eccentric compression specimens are greatly advanced and the ultimate failure form is in the final form. On the eccentric compression side, the concrete is seriously flaking, the compression side steel is exposed and the other side appears the horizontal penetration crack. When the specimen is destroyed at the normal temperature, the column cracks are obviously less than those through the high temperature, and the specimen also maintains good integrity; the column has a large number of cracks when the specimen is destroyed by the excessive temperature. The fracture is wider, the main fracture is serious and the deformation is more serious. (3) the axial stiffness of the contrast specimen at normal temperature is obviously larger than that of the specimen under high temperature. The axial deformation of the specimen under the same load is obviously larger than the contrast specimen under the normal temperature, and the stiffness degradation speed is faster. The specimens at constant temperature 60min, 120min and 180min are better than the normal temperature. The strength attenuation rates of the specimens were 16.1%, 19.3% and 24.8%, respectively. The loading eccentricity of 40mm and 80mm specimens along the X axis decreased by 9% and 14.1% respectively. The ultimate deformation of the eccentric compression specimen increased with the increase of eccentricity, which generally showed a linear trend. At high temperature, the initial stiffness of the specimen has little effect on the initial stiffness. The T-04 axial compression stiffness of the specimen with 200mm at the middle stage of the loading is obviously better than that of the abdominal rod spacing of 300mm and 400mm, and the ultimate bearing capacity changes with the horizontal ventral rod spacing. The steel content of the specimen after the high temperature increases by 15%, and the residual bearing capacity increases by 24%. The effect of different loading angles on the vertical deformation load curve of the specimen after high temperature is less, but when the test parts are near the limit load, the vertical deformation of the specimen with the loading angle of 45 degrees is obviously larger than that of the loading angle of 0 and 90 degrees.
【學(xué)位授予單位】：山東建筑大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TU398.9
[Abstract]:Profiled steel concrete special-shaped column is a new type of structural form of steel frame embedded in reinforced concrete. It is widely used in high rise buildings because of its good flexibility in layout and superior to the bearing capacity and seismic performance of ordinary concrete columns. With high rise building, it occupies a more and more important position in the present generation. The structure safety of the building is widely concerned. The damage of fire to the building is particularly serious in all kinds of disasters. Because of the high steel ratio and large area of fire, the bearing capacity loss and risk degree of the steel column are higher than that of the ordinary concrete column at high temperature. The disaster relief and later repair work provide a certain theoretical basis. It is necessary to further study the mechanical properties of the special-shaped columns after fire. This paper mainly studies the mechanical properties of the steel concrete T shaped columns after high temperature. The main work and conclusions are as follows: 11 T shaped SRC columns are designed in this paper, and the constant temperature conditions are carried out by the self-made electric heating furnace. Under the fire test of four sides, the mechanical tests were carried out on the specimens under different design variables and loading conditions (horizontal bar spacing, steel ratio, loading angle, eccentricity). The related data were arranged and analyzed. The following conclusions were obtained: (1) after the high temperature action, the surface of the special shaped column changed to gray white with the color of the concrete surface in the high temperature area. In the middle section of the back of the column, there are fine cracks in the middle section of the back of the column, and the surface of the part of the specimen has a powder substance. The temperature of the test points near the surface of the T column is higher. The temperature field of the cross section is basically the same in the 3 hours at constant temperature. In theory, it is believed that the free expansion rate of the specimen is 0.47%, 0.67% and 0.75% respectively after the same high temperature of 1H, 2h and 3H at the same temperature at the same high temperature at.600 C. The axial deformation of each specimen increases linearly with the increase of the constant temperature. The axial deformation amount decreases with the increase of steel content. (2) the failure process and failure mode of the axial compression T column under the load are basically the same as those under the normal temperature. The failure mode of the eccentric compression member is similar to that of the axial compression specimen, but the initial and the exfoliation loads of the eccentric compression specimens are greatly advanced and the ultimate failure form is in the final form. On the eccentric compression side, the concrete is seriously flaking, the compression side steel is exposed and the other side appears the horizontal penetration crack. When the specimen is destroyed at the normal temperature, the column cracks are obviously less than those through the high temperature, and the specimen also maintains good integrity; the column has a large number of cracks when the specimen is destroyed by the excessive temperature. The fracture is wider, the main fracture is serious and the deformation is more serious. (3) the axial stiffness of the contrast specimen at normal temperature is obviously larger than that of the specimen under high temperature. The axial deformation of the specimen under the same load is obviously larger than the contrast specimen under the normal temperature, and the stiffness degradation speed is faster. The specimens at constant temperature 60min, 120min and 180min are better than the normal temperature. The strength attenuation rates of the specimens were 16.1%, 19.3% and 24.8%, respectively. The loading eccentricity of 40mm and 80mm specimens along the X axis decreased by 9% and 14.1% respectively. The ultimate deformation of the eccentric compression specimen increased with the increase of eccentricity, which generally showed a linear trend. At high temperature, the initial stiffness of the specimen has little effect on the initial stiffness. The T-04 axial compression stiffness of the specimen with 200mm at the middle stage of the loading is obviously better than that of the abdominal rod spacing of 300mm and 400mm, and the ultimate bearing capacity changes with the horizontal ventral rod spacing. The steel content of the specimen after the high temperature increases by 15%, and the residual bearing capacity increases by 24%. The effect of different loading angles on the vertical deformation load curve of the specimen after high temperature is less, but when the test parts are near the limit load, the vertical deformation of the specimen with the loading angle of 45 degrees is obviously larger than that of the loading angle of 0 and 90 degrees.
【學(xué)位授予單位】：山東建筑大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TU398.9
【相似文獻(xiàn)】
相關(guān)期刊論文 前10條
1 曲恒緒;型鋼混凝土結(jié)構(gòu)計(jì)算方法的比較[J];安徽建筑;2003年06期
2 朱s，
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