畢業(yè)實(shí)習(xí)報(bào)告+文獻(xiàn)翻譯+日記.doc

土木工程專業(yè)認(rèn)識(shí)實(shí)習(xí)報(bào)告院系：土木工程與建筑系 班級(jí)： 學(xué)號(hào)： 姓名：XXX一、實(shí)習(xí)時(shí)間和地點(diǎn)：1.2011年8月29日星期一，陜西理工學(xué)院南區(qū)，實(shí)驗(yàn)樓；2.2011年8月30日星期二，漢江新城和天河望江郡，住宅樓；3.2011年8月31日星期三，漢中職業(yè)技術(shù)學(xué)院新校區(qū)；4.2011年9月1 日星期四，陜西理工學(xué)院北區(qū)，工業(yè)廠房；5.2011年9月2 日星期五，漢中市世紀(jì)陽(yáng)光商場(chǎng)。一、實(shí)習(xí)目的：走進(jìn)施工現(xiàn)場(chǎng)，親身感受建筑工地的氛圍，把理論和實(shí)踐相結(jié)合，為以后進(jìn)一步實(shí)習(xí)和工作打基礎(chǔ)。三、實(shí)習(xí)認(rèn)識(shí)感受和學(xué)到的知識(shí) 建筑設(shè)計(jì)原則：根據(jù)任務(wù)書(shū)的要求，綜合運(yùn)用所學(xué)的理論知識(shí)，遵循有關(guān)的設(shè)計(jì)規(guī)范，滿足有關(guān)功能要求，詳細(xì)收集有關(guān)資料，使設(shè)計(jì)能夠滿足相關(guān)的使用功能。 我們土木工程專業(yè)學(xué)生進(jìn)行了為期一周的認(rèn)識(shí)實(shí)習(xí)，主要是參觀施工現(xiàn)場(chǎng)，先后參觀了實(shí)驗(yàn)樓、住宅樓、綜合樓、工業(yè)廠房以及商場(chǎng)。 星期一上午參觀了我們學(xué)校南區(qū)實(shí)驗(yàn)樓的施工現(xiàn)場(chǎng)，共十三層之高。我們到達(dá)集合地點(diǎn)后，頭上都戴著工程帽；同時(shí)施工區(qū)的門上也寫(xiě)著：不戴安全帽者不得進(jìn)如施工現(xiàn)場(chǎng)；由此可見(jiàn)在建筑施工當(dāng)中首先要注意的就是安全問(wèn)題！同時(shí)，為了確保施工能順利進(jìn)行和施工的安全，工地是要用磚墻圍護(hù)起來(lái)的，只有建筑施工的各種車輛和內(nèi)部人員才可以出入，我們實(shí)習(xí)是提前經(jīng)過(guò)他們同意的！ 進(jìn)到施工區(qū)，我們一眼就看到了科技樓的結(jié)構(gòu)主體，當(dāng)時(shí)結(jié)構(gòu)主體給我的感覺(jué)就是不像建筑和不好看。這個(gè)可能是因?yàn)樗臀宜吹降倪^(guò)的已經(jīng)建好并投入使用的樓不同。主體前面有個(gè)很大的場(chǎng)地，是堆放建筑材料用的，可以看到所堆放的建材主要是鋼筋。在鋼筋堆放區(qū)我們可以看到不同型號(hào)的鋼筋是分開(kāi)放的，而且還在其前面標(biāo)明鋼筋的型號(hào)和進(jìn)場(chǎng)時(shí)間等信息。 我們跟著老師上了樓，我們踏上用鋼管和鐵網(wǎng)搭接成的梯子，開(kāi)始覺(jué)得很危險(xiǎn)，四周都有伸出來(lái)的鋼管或鐵條。在承重柱的四周有很多構(gòu)造柱，它們是用來(lái)加大墻的強(qiáng)度的，以避免因墻身過(guò)長(zhǎng)導(dǎo)致容易坍塌。一路上去，我們看到上面幾層樓板的支架還沒(méi)有拆，這些支架是用鋼管和模板組成的，鋼管很密，可見(jiàn)要承受完全沒(méi)有強(qiáng)度的混凝土板和梁需要很大的支撐力。 上到第十三層，我觀察了其中的幾條梁和柱，就像老師說(shuō)的：梁的下部是首力筋，主梁有九條，次梁有六條；上不是架立筋，主梁和次梁也不同；受力筋和架力筋之間用箍筋綁扎。柱子不一樣，三四條梁要交匯于柱，就必然要使梁的鋼筋穿過(guò)柱子，這樣使得柱頭的鋼筋十分密集，同時(shí)澆筑混凝土?xí)r也要注意密實(shí)。板的配筋一般有受力筋和架力筋，受力筋在下方，分縱橫兩路；架力筋在上方，也是縱橫兩路放著。擺好的鋼筋要用鐵絲綁扎好，為了保證面筋不被踩低下去，還要用馬蹄筋將其抬高.我們已感受到了濃厚的建筑氛圍。星期二上午我們參觀了漢江新城和天河望江郡，主要是住宅樓。我們先后參觀了住宅樓的基礎(chǔ)、墻體、柱子、樓板層、樓梯、屋頂以及門窗等部分，也重新鞏固了一下它們的作用。當(dāng)然，陽(yáng)臺(tái)、供水供電設(shè)備以及各種預(yù)留縫，還有抗震墻等我們都做了詳細(xì)的了解。以前總是對(duì)建筑工地的塔吊充滿許多疑問(wèn)，特別是塔吊是如何升降的等問(wèn)題。塔吊是工地上一種常用的起重設(shè)備，主要用的是杠桿原理。通過(guò)老師的講解和查資料，我對(duì)塔吊的升降原理有了充分的了解：塔吊塔身是模塊化設(shè)計(jì)，由多個(gè)長(zhǎng)方形塔身鋼架連接而成，在塔柱里面裝有一個(gè)油壓千斤頂，想要升高塔身就用千斤頂，然后升高，將塔柱伸長(zhǎng)，再用自身的吊臂吊起一段柱身放進(jìn)去，再縮起千斤頂，就這樣往塔身下放一個(gè)模塊。塔吊的橫桿也就是起重臂是固定在有轉(zhuǎn)盤(pán)的大套筒中，而塔吊的基座相當(dāng)于一個(gè)小套筒，大套筒在小套筒中的滑升，隨著施工高度的增加而增加小套筒的連接件，隨之將大套筒滑升至施工高度。降落過(guò)程也類同于此，大套筒向下滑落一節(jié)，小套筒就拆除一節(jié)，并用大套筒的起重臂將其降落。通過(guò)老師的講解和相關(guān)資料，對(duì)混凝土的養(yǎng)護(hù)也有了更多的了解.混凝土養(yǎng)護(hù):為了保證已澆筑好的混凝土在規(guī)定的齡期內(nèi)達(dá)到設(shè)計(jì)要求的強(qiáng)度,并防止產(chǎn)生收縮裂縫,必須認(rèn)真做好養(yǎng)護(hù)工作。針對(duì)本工程的特點(diǎn),對(duì)不同的部位選用如下的養(yǎng)護(hù)方法: 首先，對(duì)于梁板等水平構(gòu)件采用覆蓋澆水養(yǎng)護(hù)。在平均氣溫高于+5的自然條件下,用覆蓋材料對(duì)混凝土表面加以在覆蓋并澆水養(yǎng)護(hù),使混凝土在一定時(shí)間內(nèi)保持水化作用所需要的適當(dāng)溫度和濕度條件。應(yīng)符合下列規(guī)定: 覆蓋澆水養(yǎng)護(hù)在混凝土澆筑完畢后的12h以內(nèi)進(jìn)行。 澆水養(yǎng)護(hù)時(shí)間內(nèi),對(duì)采用硅酸鹽水泥、普通硅酸鹽水泥等拌制的混凝土,不得少于7d。澆水次數(shù)根據(jù)能夠保持混凝土處于濕潤(rùn)的狀態(tài)來(lái)決定。 混凝土的養(yǎng)護(hù)用水與拌制水相同。 當(dāng)日平均氣溫低于5時(shí),不得澆水。 其次，對(duì)于混凝土柱采用薄膜布養(yǎng)護(hù)。采用不透水、氣的薄膜布養(yǎng)護(hù)，用薄膜布把柱表面敞露的部分全部嚴(yán)密的覆蓋起來(lái),保證混凝土在不失水的情況下得到充足的養(yǎng)護(hù)。其優(yōu)點(diǎn)是不必澆水,操作方便,能重復(fù)使用,能提高混凝土的早期強(qiáng)度,加速模具的周轉(zhuǎn)。養(yǎng)護(hù)時(shí)必須保持薄膜布內(nèi)有凝結(jié)水。 再次，對(duì)于墻體混凝土要采用薄膜養(yǎng)生液養(yǎng)護(hù)。 薄膜養(yǎng)生液養(yǎng)護(hù)是將可成膜的溶液噴灑在混凝土表面上,溶液揮發(fā)后在混凝土表面結(jié)成一層薄膜,使混凝土表面與空氣隔絕,封閉混凝土中的水份不再被蒸發(fā),而完成水化作用。 最后，還要考慮冬期混凝土的養(yǎng)護(hù) 豎向結(jié)構(gòu)混凝土采用綜合蓄熱方法養(yǎng)護(hù)。對(duì)于水平結(jié)構(gòu),采用上鋪塑料布加保溫被的方法進(jìn)行保溫養(yǎng)護(hù),保溫被覆蓋要嚴(yán)實(shí),防止混凝土裸露,確?；炷敛皇軆?。星期三我們參觀了漢中職業(yè)技術(shù)學(xué)院新校區(qū)，在這里，我主要向老師了解了一下箍筋的相關(guān)知識(shí)：箍筋用來(lái)滿足斜截面抗剪強(qiáng)度，并聯(lián)結(jié)受力主筋和受壓區(qū)混凝土使其共同工作，此外，用來(lái)固定主鋼筋的位置而使構(gòu)件（梁或者柱）內(nèi)各種鋼筋構(gòu)成鋼筋骨架的鋼筋。 箍筋分類：分單肢箍筋、開(kāi)口矩形箍筋、封閉矩形箍筋、菱形箍筋、多邊形箍筋、井字形箍筋和圓形箍筋等。 箍筋設(shè)置：箍筋應(yīng)根據(jù)計(jì)算確定，箍筋的最小直徑與梁高h(yuǎn)有關(guān)，當(dāng)h800mm時(shí)，不宜小于6mm；當(dāng)h800mm時(shí)，不宜小于8mm。梁支座處的箍筋一般從梁邊（或墻邊）50mm處開(kāi)始設(shè)置。支承在砌體結(jié)構(gòu)上的鋼筋混凝土獨(dú)立梁，在縱向受力鋼筋的錨固長(zhǎng)度范圍內(nèi)應(yīng)設(shè)置不少于兩道的箍筋，當(dāng)梁與混凝土梁或柱整體連接時(shí)，支座內(nèi)可不設(shè)置箍筋。 箍筋加密：箍筋加密區(qū)是對(duì)于抗震結(jié)構(gòu)來(lái)說(shuō)的，根據(jù)抗震等級(jí)的不同，箍筋加密區(qū)設(shè)置的規(guī)定也不同。一般來(lái)說(shuō)，對(duì)于鋼筋混凝土框架的梁的端部和每層柱子的兩端都要進(jìn)行加密。梁端的加密區(qū)長(zhǎng)度一般取1.5倍的梁高。柱子加密區(qū)長(zhǎng)度一般區(qū)1/6每層柱子的高度。但最底層（一層）柱子的根部應(yīng)取1/3的高度。 箍筋加密范圍：加密范圍是按照規(guī)范規(guī)定來(lái)的，沒(méi)有具體的計(jì)算公式。柱子和梁的加密區(qū)箍筋的設(shè)置方法為：柱箍筋加密范圍是：底層柱的柱根加密區(qū)長(zhǎng)度應(yīng)取不小于該層柱凈高的1/3，以后的加密區(qū)范圍是按柱長(zhǎng)邊尺寸、樓層柱凈高的1/6,及500mm三者數(shù)值中的最大者為加密范圍。梁箍筋加密范圍：加密范圍從柱邊開(kāi)始，一級(jí)抗震等級(jí)的框架梁箍筋加密長(zhǎng)度為2倍的梁高，二、三、四級(jí)抗震等級(jí)的框架梁箍筋加密長(zhǎng)度為1.5倍的梁高，而且加密區(qū)間總長(zhǎng)均要滿足大于500mm，如果不滿足大于500mm，按500mm長(zhǎng)度進(jìn)行加密。 星期四參觀了北校區(qū)機(jī)械學(xué)院的實(shí)習(xí)廠房，一座比較老式的工業(yè)廠房建筑，外表像以前的民用建筑。用的是斜屋頂，這樣有利于排水，室內(nèi)的凈高明顯高于民用建筑。兩側(cè)柱子是典型的工業(yè)廠房的柱式，上部有牛蹄，用于安裝吊車的軌道。其寬面也個(gè)立了兩根抗風(fēng)柱，這些柱和每隔一段距離設(shè)的梁使墻能有足夠的剛度以抵抗強(qiáng)風(fēng)的荷載。在一個(gè)高溫鍋爐旁的柱子，外圍貼了防火材料，保護(hù)柱子。實(shí)驗(yàn)室的作用在于給結(jié)構(gòu)設(shè)計(jì)師一個(gè)能檢驗(yàn)其設(shè)計(jì)可行性的場(chǎng)所，這對(duì)建筑物的安全性和可靠性是至關(guān)重要的，同時(shí)也是科學(xué)實(shí)驗(yàn)所必備的。在實(shí)驗(yàn)室，我們看到了許多大型的實(shí)驗(yàn)儀器，它們實(shí)質(zhì)上都是給試件提供壓、拉、剪方面的應(yīng)力，從而檢測(cè)其能承受力的能力，也就是它們的強(qiáng)度。 在實(shí)驗(yàn)室，我們還可以看到做各種構(gòu)件的模型。 當(dāng)然，我們不僅看了各種機(jī)器，而且對(duì)建工實(shí)驗(yàn)有了初步的認(rèn)識(shí)，并建立起一種實(shí)驗(yàn)檢驗(yàn)假設(shè)的觀念，這次參觀應(yīng)該是有比較大的收獲的。 通過(guò)這幾天的現(xiàn)場(chǎng)參觀，我們對(duì)建筑有了一般的感性認(rèn)識(shí)，但對(duì)于施工的過(guò)程與一些細(xì)部問(wèn)題和可能發(fā)生的危險(xiǎn)問(wèn)題我們知道得還比較少。星期五我和舍友四人自行參觀了漢中市的世紀(jì)陽(yáng)光商場(chǎng)。當(dāng)然，商場(chǎng)是已裝修好并投入使用了，四周當(dāng)然沒(méi)有伸出來(lái)的鋼管或鐵條等。為了充分利用空間，樓層間的凈高不高于3米的。在這里，我們幾個(gè)主要了解了墻面裝修需要注意的一些事項(xiàng)。 墻體的裝修，有很多種，下面是常見(jiàn)的幾種做法的情況：一、乳膠漆。是目前墻面處理的主流。 在二次裝修中，乳膠漆涂飾前，對(duì)于原涂料層的處理基于下面幾種原則： 1、新房子的墻面一般只需要用粗砂紙打磨，不需要把原漆層鏟除。 2、普通舊房子的墻面一般需要把原漆面鏟除。方法是用水先把其表層噴濕，然后用泥刀或者電刨機(jī)把其表層漆面鏟除。 3、對(duì)于年久失修的舊墻面，表面已經(jīng)有嚴(yán)重漆面脫落，批燙層呈粉沙化的，需要把漆層和整個(gè)批燙鏟除，直至見(jiàn)到水泥批燙或者磚層。 4、然后用雙飛粉和熟膠粉調(diào)拌打底批平，再就是涂飾乳膠漆了，面層需涂2遍至3遍，每遍之間的間隔時(shí)間以24小時(shí)為佳。須提醒的是，很多工業(yè)涂料都有或多或少的毒性，施工時(shí)要注意通風(fēng)，施工后也要至少一周以上時(shí)間揮發(fā)后方能入住。 二、噴涂。是水溶性涂料的一種涂刷方法，利用水包油的特點(diǎn)，使用加壓噴色槍進(jìn)行施工?？尚纬啥喾N顏色紋理，效果淡雅，有立體感。噴涂施工方式的最主要優(yōu)點(diǎn)是施工快速，可大大縮短施工工期。其缺點(diǎn)是后期維護(hù)困難，容易因小部分披落而使整個(gè)表面?zhèn)劾劾?，除非大面積處理，否則無(wú)法恢復(fù)原狀。另外要注意的是，如果對(duì)金屬表面進(jìn)行噴涂處理，最好是選用金屬漆(磁漆類)。三、墻紙。裝修相當(dāng)普遍。主要有紙?jiān)靿?、化纖墻紙、塑料墻紙。而布質(zhì)的墻紙一般稱為墻布，不劃歸墻紙一類。墻紙可印圖案，圖案變化多端，色澤豐富，且施工方便快捷。墻紙的施工，最主要的關(guān)鍵技術(shù)是防霉和處理伸縮性的問(wèn)題： 1） 防霉的處理。墻紙張貼前，需要先把基面處理好，可以雙飛粉加熟膠粉進(jìn)行批燙整平。待其干透后，再刷上一兩遍的清漆，然后再行張貼。 2） 伸縮性的處理。墻紙的伸縮性是一個(gè)老大難問(wèn)題，要解決就是從預(yù)防著手。一方面一定要預(yù)留0.5mm的重疊層，有一些人片面追求美觀而把這個(gè)重疊取消，這是不妥的。另外，盡量選購(gòu)一些伸縮性較好的墻紙。四、瓷磚。瓷磚多數(shù)應(yīng)用于廚房、廁所，陽(yáng)臺(tái)等墻面。瓷磚裝修的最大優(yōu)點(diǎn)是耐臟。瓷磚裝修一個(gè)主要問(wèn)題是防水層的處理。因?yàn)樵趶N廁等地方多數(shù)要用水。所以墻面的防水更應(yīng)高度注意。沒(méi)有做防水的新房子或者需要更換瓷片的舊房子，都需要重新做防水層。防水層的處理主要辦法是：地面及墻面1米高度的宜用專業(yè)的防水劑，例如911號(hào)防水劑。而墻面高于1米的位置可以選用便宜一點(diǎn)的瀝青油做防水。如果經(jīng)濟(jì)不充許，也可以直接用瀝青或者樹(shù)脂做地面防水。地面及地面20厘米的位置一定要做厚點(diǎn)。新房子做防水層，施工后要注意檢查表面應(yīng)無(wú)空隙。舊房子拆除舊瓷磚面后，需要先簡(jiǎn)單做水泥批燙后，方可做防水層。瓷磚施工后，如果出現(xiàn)破損需要進(jìn)行維修時(shí)，要小心，如果該位置偏低，可能防水層在拆除時(shí)破裂，在補(bǔ)上新磚前，同樣進(jìn)行進(jìn)行防水層修復(fù)，方可鋪貼瓷磚。裝修完畢后，盡量避免在低于1米高度的地方鉆打孔眼。五、木板飾面。木板飾面是現(xiàn)在一些高檔裝修的做法。一般是在9厘底板上貼3厘飾面板，再打上蚊釘固定。木板飾面可作各種造型，且木飾面板具有各種天然的紋理，可給室內(nèi)帶來(lái)華麗的效果。無(wú)論何種裝修，都要保持表面的清潔。飾面板買進(jìn)場(chǎng)后就應(yīng)該刷一遍清漆做為保護(hù)層。木板飾面中，如果采用的是飾面板裝飾的，可能技術(shù)問(wèn)題不大，但如果采用的是夾板裝飾，表面刷漆(混油)的做法的話，那么可能就有防開(kāi)裂的要求了。木飾面防開(kāi)裂的做法是：1） 接縫處要45度角處理。其接觸處形成三角形槽面。2） 在槽里填入原子灰膩?zhàn)?，及貼上補(bǔ)轂鏈?表面調(diào)色膩?zhàn)优健?4） 再進(jìn)行其他的漆層處理。木飾面的固定用的釘一定要使用蚊釘，在表層處理時(shí)，用調(diào)色膩?zhàn)犹钇郊纯?。六、石材飾面。石材裝飾墻面的做法，屬于高檔裝修做法。一般多采用進(jìn)口大理石，造價(jià)較高。在墻面裝修中采用石材施工，主要分為兩種做法：濕貼法和干掛法兩種。1、 濕貼法與瓷磚的鋪設(shè)是一樣的，具體施工方法請(qǐng)參閱本文上款有關(guān)瓷磚的施工部分。2、 干掛法是目前在建筑業(yè)備收歡迎的做法。但由于干掛法需要占用額外的空間位置，所以對(duì)于面積較小的室內(nèi)裝修時(shí)，較少采用。 總結(jié) ： 在實(shí)習(xí)中我們的確接觸了不少實(shí)際應(yīng)用的東西，但離實(shí)際水平較高的生產(chǎn)方式和比較先進(jìn)的技術(shù)還有很大的差距。我發(fā)現(xiàn)我們看到的生產(chǎn)工藝都是不算先進(jìn)的，就像我們看錄像的支模方式在科技樓還沒(méi)有用上，而人家在八十年代初就已經(jīng)開(kāi)始使用了，這可能是因?yàn)槭┕挝坏奈镔Y匹備不足，但先進(jìn)的生產(chǎn)工藝確實(shí)可以提高施工進(jìn)度和生產(chǎn)質(zhì)量。 從建筑發(fā)展的趨勢(shì)來(lái)看，鋼結(jié)構(gòu)越來(lái)越受到人們的重視和肯定，研究鋼結(jié)構(gòu)的受力和增強(qiáng)鋼結(jié)構(gòu)的耐火性是一個(gè)亟待深入的課題。當(dāng)然我們還是要立足于鋼筋混凝土結(jié)構(gòu)的學(xué)習(xí)，通過(guò)學(xué)習(xí)和實(shí)踐使我們對(duì)建筑的構(gòu)造有更深入的了解，并且不能忽視某些可能發(fā)生的隱患，以確保我們建造的高樓真正地能應(yīng)付各種緊急情況。這次實(shí)習(xí)時(shí)間雖然很短，但收獲不小，對(duì)今后的學(xué)習(xí)和實(shí)踐起到了一定的導(dǎo)向作用。以后的實(shí)習(xí)可能會(huì)更辛苦，但我期待著風(fēng)雨的來(lái)臨，為理想撐起一片藍(lán)天。英文部分：出處：Vo12l No3 Journal oI Wuhan University of Technolo,一Mater iEd Sept2006標(biāo)題：Charactersitics of Stressstrain Curve of High Strength Steel FiberReinforced Concrete under Uniaxial Tension作者：YANG Meng HUANG Chengkui WANG Jizhong(State Key Laboratory of Coastal and Ofshore Engineering，Department of Civil, Engineering，Dalian University of Technology，Oalian 1 16023，China)正文：Abstract： A whole of110 specimens dividedinto 22 groups weretestedwith vooing the volumefractionofsteelfibers and the matrix strength ofthese specimensThe stress-strain behaviors offotypes of steelfiber reinforced concrete(SFRC)l2der uniaxial tension were studied experimentally n the matrix strength and the fiber content increase，the tensile stress and tensile strain vary diferently according to thefiber typeThe mechanisms ofreinforcng ctfor diferent types offiber were analyzed and the stress-strain cllltofthe specimens wereplottedSome experimentalfactorsfor SesS or strain ofSFRC were nA tensile tongh,s Hlolas Re0 5introduced to evaluate the toughness characters of SFRC l2der uniaxial tensionMoreover，theormala ofthetensile stress-strain cllofSFRC was regressedThe theoretical c11iand the experimental 0， well，whichcan be usedfor references in constructionKey words： steelfiber reinforced concrete； high strength； uniaxial tension； stress-strain c11i：soften characteristics1 IntroductionThe tensile properties of concrete can be enhanced substantially by incorporating high strength and small diameter short steel fiberswhich lcads to the steel fiber reinforced concrete(SFRC)In conventional SFRC，thesteel fiber content is usually within the ran ge of 02 一2 by volumeAt such a low 6her contentthe tensileresponse of SFRC would assuIne a nonh ardening typewhich is characterized by the widening of a single crack，similar to an unreinforeed concrete e contribution oftibers is 印parent in the postcracking response， represented by an increase in postcracking ductility due to thework associated with pullout of fibers bridging a failurecrackHowever，improvements in some other propertiesare insignificant Moreover，the softening segment ofthe stressstrain curve of SFRC th such a low fiber content under uniaxial tension is dificult to be got with normalexperimental methodsMany works have been done tofind a suitable and relatively easy way to analyze the tensile characteristics 。 And it was reported that the wholecurve could be got on a normal testing machine with sti if_ening components addedIn this article，the stressstrain be havior of SFRCunder uniaxial tension Was an alyzed for different types offiberTh e tensile characteristics of SFRC influeneed bythe matrix strength and the steel fiber content were studiedalsoIn addition，the stressstrain curves of high strengthSFRC with different factors were well acquired(Received：April 17，2005；Accepted：March 6，2006)YANG Meng(楊萌)：Ph D candidate；E-mail：yangmengstudentdluteducn* Funded by Regulation Revising Item of China Association for Engineering Corktmction Standardization(CECS 1 5：2000)2 ExperimentalTh e specimens were tested on a 60 kN universal testing machineFour high steel bars were added to enhan cethe stiffness of the testing machineIn addition，spherichinges were used to abate the initial axial eeeentricity ofthe specimensIt was ensured that specimens should be pulled 1113一der uniaxial tension by aajusting the four high strength bolts which connect the specimens to the CroSSbeamAndthe difference between the tensile strains of the oppositesides of the specimen should be less than 1 5 of theirmean valueWhen the fiber content was low (0 and 05 by volume)，the cyclicquire the whole stressstrain21 M aterialstension way was used to aeeun ，e Four types of steel fibers shown in Tabk 1 were chosen for this test ree of these fibers (F1，F(xiàn)2 and F3)were hookedend and the other one(F4)was smothTh ree concrete mixtures，shown in Table 2，were investigatedWater reducing agents were used in C60 andC80 mixes(DK一5 made by Dalian Structure Research Institute and Sika made in Switzerland respectively) ecompressive strengths of these C30，C60，C80 mi xes weredeterm ined according to“Test Methods Used for Steel Fiber Reinforced Concrete”(CECS 13：89)8 3 at 28 daysusing 150 Bin150 Bin150 Bin cube sAveraged resuits for 3 specimens are given in Table 20rdinary Portland cement(yielded by Dalian Huaneng Onod a CementCompany)of 325 and 525 (according to China staBdard)were chosenRiver sand(modulus of fineness is 26)and crushed limestone coarse aggregates(520 Bin)were used維普資訊 Vo121 No3 YANG Me et fzf：Stud 。n Stress-strain CunP()f High StrPl1州1 Steel Fil leiI1tbrcet 133Note：F忙r nsije crack stress of SFRC；f(r nsile crack stress of plain concrete n the Sallle mix proportion；fi Uhimatc tensile strength of SFRC UfinlHfe tensile strength of plain concrete with the sanle mixing proportion22 SpcimemThe tensile specimen was bonded to steel paddingplates at both ends by tygoweldA total of 1 1 0 specimenswere divided into 22 groups according to certain parametersTh e parameters of these specimens are shown in Table 323 ItemsAt the age of 28 daysplain concrete and steel fiberconcrete specimens were tested for tensile strength，resqectively Th e tensile stressstrain curves were ac。quiredMany other tensile characters of the high strengthsteel fiber concrete such as tensile work，etc were calculated also3 Results and Discussion31 Crack stress and ultim ate tensile strengthTh e crack stress and ultimate tensile strength of differentspecimens are listed in Table 3The addition ofsteel fibers into concrete increased its crack sress an d ultimatetensile strengthAnd the ratios of these two paraiTleters of SFRC to those of plain concreue(with the samemix proportion)are given in Table 3，too311 Effect of matrix strength an(1 fiber typeFH)m Fable 3it(an be seen that the effects of steelfibers 0n crack stress are little influenced by the matsixstrengthTI1at is h)savwhen the nlatrx strength i117reas-維普資訊 134 Journal of Wuhan University of Technology一MaterSe iEd Sept2006es，the ratios of crack stresses of SFRC ( th the sametype of fibers contained)to those of plaio concrete oneswith the same mix proportion are invariableHowever，the condition for ultimate tensile strengthis differentWhen the matrix strength increasesthese ratics of ultimate tensile strengths(shown in Table 3)varydissimilarly according to the type of steel fiberMoreoverthe increments are bigger than those of crack stressThe heightening efficiency of fiber F1 for ultimatetensile strength rises as matrix strength increasesIt isbecause that the strength of this kind of fiber is very high(1 100 MPa)No fiber broken was observed during thetest and the hookedends of the fibers were straightenedwhen the matrix strength was high(C80)The higher thema trix strength this kind of steel fiber takes on itsstrengthening effect more eficiently for the increasing ofbond stressTh e strengths of fibers F2 and F3 are midhigh(700 MPa)Thev all have boked ends and bothof their surfaces are coarse en the matrix strength washigh(C80)fiber breaking occurred in the testAnd thisphenomenon impaired the heightening eficiency of thesetwo kinds of steel fiberSo they should be used in middlestrength concrete to exert their strengthening efect moreeficientlyFiber F4 is smoothand its bond stress withma trix is comparatively lowT1ereforeits strengtheningeffect is 1ess notable than those of other kinds of fiberBecause of the low bond stressno fiber broken was foundduring the test and its heightening eficiency for ultimatetensile strength rises as matrix strength increases312 Effect offiber contentTh e effect of fiber content on the crack stress and u1timate tensile strength was investigated for SFRC contained fiber F3And the fiber content varied from 05to 15 by volume(shown in Table 3)It can be seenfrom Fig1 and Fig2 that as the fiber content increasesthe crack stress and ultimate tensile strength of SFRC improve obviouslyMoreoverthe rising trends of the curvesin these two figures are stupendously similarIn otherwords，the effect of fiber content on the characters of tensile stress of SFRC is positive and consistentTable 4 Fjber tvae factorsFiber code dFlF2F3F4O642O86207940589Th e tensile strength of SFRC can be calculated withthe follow formula：= (1+a ) (1)where， is the ultimate tensile strength of sFRc； theultimate tensile strength of plain concrete with thesame mixing proportion；a，the fiber type factor，which isSh。1 in Table 4； ，： 告， isIhe ber content 0f v。l愀aI1d吾is the aspect rali。0fsteel fibers32 Tensile strain and touehness characters321 Crack strain and the strain at peak tensile lcadTh e tensile strains welacquired by averaging thereadings of the four displacement sensors fixed around thespecimenIn addition，the specimens whose differencebetween the tensile strains of its opposite sides is largerthan 15 of their mean value were blanked outTh e crack strain or the strains at peak tensile lcad ofSFRC are much biger than those of plain concrete(asshown in Table 5)And the increments go up as the matrix strength or the fiber content increasesCompared tothat on crack strainthe increscent effect of steel fiber onthe strain at peak tensile lcad is more remarkable322 Tensile work and toughness modulusTh e tensile work was defined as the area underthe load-displacement curve from 0 to 05 rainMoreover，a tensile toughness modulus was introduced(shownin Table 5)It was defined as：s 贏 (2)where， is the ultimate tensile strength of SFRC；A，the area of the cross section of specimenBoth these two param eters were qu oted to evaluatethe toughness characters of SFRC under uniaxial tensionTh e tensile toughness modulus is a dimensionless factorCompared to what the tensile work doesit can avoid theinfluence of the ultimate tensile strength when studyingthe toughness of SFRCIt call be found from Table 5 that the altering regularities of these two factors along with the changes of matrix strength and fiber content are approximateTh erefore，the emphasis of analysis was put on the toughnessmodulusTh e relationship between the matrix strength andtoughness modulus of SFRC th four kinds of steel fiberare shown in Fig3whose fiber contents are all 1Oby volumetogether with that relationship of plain concreteThe tensile toughness of SFRC is much better thanthat of plain concreteTh e tensile toughening efect ofsteel fiber iS remarkableAs the ma trix strength risesthebrittleness of concrete increases obviously，and then thetensile toughness of plain concrete falls downThis pbenomenon was also found on specimens containing fiber F1and F2Th e pulling out of fiber F1 from concrete is infact a process of hokends being straightened and thematrixs being crushed around the hokendWhen thehoked end is straightened at lastthe tensile lcad fallsdown quicklyThe higher the concrete strength。the larger the rigidity of the ma trix and the shorter the time thatthe process mentioned above lastsTh usthe stress-straincurve falls down more qu ickly，and then the toughnessmodulus decreasesHowever，the toughening efect of fiber F1 is the best am ong these four kinds of steel fiberTh e aspect ratio of fiber F2 is the least。and when thematrix strength is high， ber breaking occursT1eref0re，the t0ughness modulus f ls d0wn c0ntinuallyLs the matdxstreng rises中文部分： 高強(qiáng)度鋼纖混凝土應(yīng)力應(yīng)變特性一、介紹直徑很小的鋼纖維用于混凝土結(jié)構(gòu)可以大大的提高混凝土的抗拉承載能力。在一般情況下混凝土中摻鋼纖維的體積比利在0.22.0之間。在很小比例下，鋼筋混凝土的張拉響應(yīng)可假設(shè)為不硬化的類型，它有加大單個(gè)裂縫擴(kuò)展性質(zhì)很像無(wú)鋼筋的素混凝土，鋼纖維對(duì)混凝土開(kāi)裂之后性能的改善作用更加明顯，可以通過(guò)控制裂縫