土木工程專業(yè)外文翻譯---現(xiàn)澆樓板裂縫的產生與防治

1、<p>　　roduction and prevention and cure of the crack of skyscraper</p><p>　　Along with the speeding of town house construction step, not a few areas with small residences set up one after another, many

2、inhabitants move continuously into the new residence, their quality to housing request is more and more high, particularly pay attention to very much to some cracks circumstances which sprinkle building plank to appear n

3、ow, worry these cracks' aring end will cause insecurity trouble, but in succession to building quality direct the section hurl tell.</p><p>　　Such as once the some city develop a company to set up 6 laye

4、rs of floor residence 16 totally, constructing area about 100,000 square meters, the brick mixs structure, the beginning repairs, one steps 2 box off with the brick wall, each one's establishing a turn of beam togeth

5、er building plank is togetherwhole to sprinkle, the plank thick 100 mms, concrete mark number is C20, house long about with 80-90 ms, don't establish flexible sew, first floor is the 2.2 m garage layer, the C20 reinf

6、orcing </p><p>　　1, cause now main reason of sprinkling the plank crack is the constringency of concrete, the concrete is in the nature the hardening the process, because water evaporates continuously, but t

7、he physical volume gradual constringency, but the plank is on all sides to be subjected to a stipulation of, can't flex freely, so when the constringency of concrete cause to sprinkle knothole stipulation now should

8、the dint exceed certain limit, certanly will cause to sprinkle plank to open crack now.And the</p><p>　　2, construct too early on the cast-in-place board , add and carry on one's shoulder or back the cra

9、ck caused. " norm of inspection of quality of structural construction of concrete " stipulates , before the concrete intensity reaches 1.2N/mm2, can't trample or install template and support on it . But dev

10、eloper , for race against time , catch up with progress , or concrete at , congeal and congeal stage after all for the first time still in water at the good cast-in-place board just, take up the </p><p>　　3,

11、 the crack which the temperature change causes. As everybody knows, the cement condenses and hardens fast at room temperature, the characteristic such as being great of heat of hydration, especially in summer, after the

12、concrete is built, the release amount of the heat of hydration is great, the concrete is under the high temperature, can't get and water maintenance in time , and desiccate and shrink, make concrete take place dry to

13、 split , result in fracturing finally. Investigation find in t</p><p>　　4, the house is crossed too long to set up the essential expansion joint , is the reason which causes the crack too. The developer is i

14、n order to save the land, often take the length of the house into account , make the house whole too long, set up expansion joint either, because of lack essential expansion joint, freedom flexible degree in house reach

15、or exceed should set up interval that expansion joint require ,, will present the crack too. </p><p>　　5, the board is defeated by the muscle and sunk in the crack produced . In the course of constructing, b

16、ecause constructors operate barbarously, trample the reinforcing bar arbitrarily , cause and shoulder the muscle and sink, the antiabrasion layer is too big, reduce the sectional effective height of the board, make the b

17、earing capacity of the board unable to reach the requirement of ones that design, thus cause the production of the crack of board. </p><p>　　Effective height, make the bearing capacity of the board unable to

18、 reach the requirement of ones that design, thus cause the production of the crack of board. How to prevent and cure the production of the board crack of cast-in-place board, according to the construction experience for

19、many years, offer some following prevention measures, suitable for consulting : </p><p>　　1, Do well cast-in-place board maintain , work , guarantee concrete intensity , prevent and cure important link that

20、crack produce one of conscientiously. The norm stipulates , must cover and keep maintenance warm in 12 hours after the concrete is built at room temperature, ordinary cement is no less than 7 days, if the one that ignore

21、d to concrete watered maintenance, on one hand it reduce concrete intensity, on the other hand it make concrete to be in the course of hardening too late to supple</p><p>　　2, cast-in-place board don't p

22、ass morning people , pile material , He Shi load , because concrete have a sclerosis course build ,, just have intensity; In this course , should maintain the concrete , can't exert any external force to the concrete

23、 . In a situation that the concrete has not had certain intensity yet , concentrate on , pile up construction material or prop up mould stand , rest on it, that brought the cast-in-place board is not intensity like this,

24、 but more cracks. So, must make su</p><p>　　3, shoulder thickness of antiabrasion layer of the muscle the strict control panel . Cast-in-place board shoulder muscle put , on board , have roof beam according

25、to designing requirement through generally put on reinforcing bar of roof beam or stay with reinforcing bar lashing of roof beam cut off ,. For control good to shoulder muscle antiabrasion layer thickness , must adopt Φ1

26、0 - Φ14 reinforcing bar horse stool, vertical-horizontal interval 800mm come fixed position to shoulder muscle from s</p><p>　　4, control good sand , stone in a foot-path and mud content strictly. The thick

27、sand in the cast-in-place board should be selected for use, a stone of foot-path between 0.25-0.5mm, the mud content of grit can't exceed 1% . Sand,, stone grains of foot-path careful and too light, mud content too b

28、ig, will reduce concrete intensity, will make the concrete produce the crack finally.</p><p>　　5, dispose certain amounts of angle muscles in four corners of the board , radiate the muscle . Take place in bo

29、ard corner phenomenon this more to cast-in-place board crack, corner set up Φ all around in boardThe length radiates the muscle for about 1800mm, so as to meet demands of angle stress of the board, the stress sphere of a

30、ction of making the cast-in-place board produce the crack conforms with radiation muscle, thus change and control the production of the crack effectively</p><p>　　forced concrete structure reinforced with an

31、 overviewRein</p><p>　　Since the reform and opening up, with the national economy's rapid and sustained development of a reinforced concrete structure built, reinforced with the development of technology

32、 has been great. Therefore, to promote the use of advanced technology reinforced connecting to improve project quality and speed up the pace of construction, improve labor productivity, reduce costs, and is of great sign

33、ificance.</p><p>　　Reinforced steel bars connecting technologies can be divided into two broad categories linking welding machinery and steel. There are six types of welding steel welding methods, and some a

34、pply to the prefabricated plant, and some apply to the construction site, some of both apply. There are three types of machinery commonly used reinforcement linking method primarily applicable to the construction site. W

35、ays has its own characteristics and different application, and in the continuous development</p><p>　　1、 steel mechanical link </p><p>　　1.1 radial squeeze link</p><p>　　Will be a

36、 steel sleeve in two sets to the highly-reinforced Department with superhigh pressure hydraulic equipment (squeeze tongs) along steel sleeve radial squeeze steel casing, in squeezing out tongs squeeze pressure role of a

37、steel sleeve plasticity deformation closely integrated with reinforced through reinforced steel sleeve and Wang Liang's Position will be two solid steel bars linked</p><p>　　Characteristic: Connect inten

38、sity to be high, performance reliable, can bear high stress draw and pigeonhole the load and tired load repeatedly.</p><p>　　Easy and simple to handle, construction fast, save energy and material, comprehens

39、ive economy profitable, this method has been already a large amount of application in the project.</p><p>　　Applicable scope : Suitable for Ⅱ , Ⅲ , Ⅳ grade reinforcing bar (including welding bad reinforcing

40、bar ) with ribbing of Ф 18- 50mm, connection between the same diameter or different diameters reinforcing bar .</p><p>　　must squeeze link</p><p>　　Extruders used in the covers, reinforced axis

41、along the cold metal sleeve squeeze dedicated to insert sleeve Lane two hot rolling steel drums into a highly integrated mechanical linking methods.</p><p>　　Characteristic: Easy to operate and joining fast

42、and not having flame homework , can construct for 24 hours , save a large number of reinforcing bars and energy.</p><p>　　Applicable scope : Suitable for , set up according to first and second class antideto

43、nation requirement -proof armored concrete structure ФⅡ , Ⅲ grade reinforcing bar with ribbing of hot rolling of 20- 32mm join and construct live.</p><p>　　1.3 cone thread connecting</p><p>　　U

44、sing cone thread to bear pulled, pressed both effort and self-locking nature, undergo good principles will be reinforced by linking into cone-processing thread at the moment the value of integration into the joints conne

45、cting steel bars.</p><p>　　Characteristic: Simple , all right preparatory cut of the craft , connecting fast, concentricity is good, have pattern person who restrain from advantage reinforcing bar carbon con

46、tent.</p><p>　　Applicable scope : Suitable for the concrete structure of the industry , civil building and general structures, reinforcing bar diameter is for Фfor the the 16- 40mm one Ⅱ , Ⅲ grade verticalit

47、y, it is the oblique to or reinforcing bars horizontal join construct live.</p><p>　　conclusions</p><p>　　These are now commonly used to connect steel synthesis methods, which links technology i

48、n the United States, Britain, Japan and other countries are widely used. There are different ways to connect their different characteristics and scope of the actual construction of production depending on the specific pr

49、oject choose a suitable method of connecting to achieve both energy conservation and saving time limit for a project ends.</p><p>　　References</p><p>　　1 、construction manual write the group. Co

50、nstruction manual. Beijing: China Construction Industry Press, 1992.</p><p>　　2 、JGJ107-96 reinforcing bar machinery connects the common technical regulation 3 GB 1499-91 The armored concrete uses the reinfo

51、rcing bar. </p><p>　　4 、GB with ribbing of hot rolling 13013-91 The armored concrete uses the round reinforcing bar of hot calendaring.</p><p>　　現(xiàn)澆樓板裂縫的產生與防治</p><p>　　隨著城市住宅建設步伐的加快，

52、不少住宅小區(qū)相繼建成，許多住戶陸續(xù)搬進新居，他們對住房的質量要求越來越高，尤其對一些現(xiàn)澆樓板出現(xiàn)的裂縫情況非常關注，擔心這些裂縫最終會引發(fā)不安全事故，而紛紛向建筑質量監(jiān)督部門投訴。 </p><p>　　如某市一開發(fā)商共建6層樓住宅16幢，建筑面積約10萬平方米，磚混結構，初裝修，一梯二戶用磚墻分隔，每層設有圈梁同樓板整澆，板厚100mm，混凝土標號為C20，房屋長約80-90m之間，不設伸縮縫，底層為2.2m車

53、庫層，基礎采用C20鋼筋籠灌注樁。該小區(qū)于2003年10月完工，竣工驗收時，未發(fā)現(xiàn)明顯裂縫，在住戶裝修時，發(fā)現(xiàn)樓板有裂縫出現(xiàn)，故聯(lián)名向質量監(jiān)督部門投訴，經實地踏看，16幢房屋均存在深淺不一的裂縫。裂縫寬度在0.2mm-0.4mm之間，裂縫位置絕大多數(shù)處在板四角，朝陽處更為明顯。于是，質監(jiān)部門組織有關單位，首先對房屋沉降量和傾斜度進行復查，結果都在允許范圍內，再查看施工圖紙也符合有關規(guī)范要求。鑒于上述情況，經過認真分析，確認裂縫原因有以下

54、幾點： </p><p>　　1、引起現(xiàn)澆板裂縫的主要原因是混凝土的收縮，因為混凝土在自然硬化過程中，由于水份不斷蒸發(fā)，而體積漸漸收縮，但板四周受支座的約束，不能自由伸縮，所以當混凝土的收縮所引起現(xiàn)澆板的約束應力超過一定限度時，勢必引發(fā)現(xiàn)澆板開裂。而且裂縫部位多發(fā)生在應力比較集中的地方——板角處，卻與墻陰角線相垂直。 </p><p>　　2、現(xiàn)澆板上過早施工，加荷引起的裂縫?！痘炷两Y構

55、工程施工質量驗收規(guī)范》規(guī)定，混凝土強度達到1.2N/mm2前，不得在其上踩踏或安裝模板及支架。但開發(fā)商為了搶時間，趕進度，在剛澆好的現(xiàn)澆板上或混凝土尚處在初凝和終凝階段，就任意踩踏，搬運材料，集中堆放磚塊、砂漿、模板等。過早的加荷，人為地造成了現(xiàn)澆板裂縫。 </p><p>　　3、溫度變化引起的裂縫。大家知道，水泥在常溫下具有凝結硬化快，水化熱大等特點，尤其在夏天，混凝土澆筑后，水化熱釋放量大，混凝土在高溫下，

56、得不到及時澆水養(yǎng)護，而失水收縮，使混凝土發(fā)生干裂，最終導致開裂。調查中發(fā)現(xiàn)，居多板角裂縫都處在遭受太陽直接曝曬的朝陽面。 </p><p>　　4、房屋過長未設置必要的伸縮縫，也是導致裂縫的原因。開發(fā)商為了節(jié)省土地，往往不顧及房屋長度，使房屋整體過長，也不設置伸縮縫，由于缺少必要的伸縮縫，當房屋的自由伸縮度達到或超過應設置伸縮縫要求的間距時，也會出現(xiàn)裂縫。 </p><p>　　5、板負筋

57、下沉產生的裂縫。在施工過程中，由于施工人員野蠻操作，任意踩踏鋼筋，致使負筋下陷，保護層過大，減少了板截面的有效高度，使板的承載能力達不到設計的要求，從而導致板裂縫的產生。 </p><p>　　如何防治現(xiàn)澆板板裂縫的產生，根據(jù)多年的施工經驗，提供以下一些防治措施，可供參考： </p><p>　　1、認真做好現(xiàn)澆板養(yǎng)護工作，是保證混凝土強度、防治裂縫產生的重要環(huán)節(jié)之一。規(guī)范規(guī)定，常溫下混凝

58、土澆筑后12小時內，必須覆蓋保溫養(yǎng)護，普通水泥不少于7天，如果忽視對混凝土的澆水養(yǎng)護，一方面會降低混凝土強度，另一方面會使混凝土在硬化過程中來不及補充水分，因而大量缺水而產生裂縫。所以做好混凝土的澆水養(yǎng)護，既可減少溫度產生的裂縫，也可降低混凝土收縮而產生的裂縫。 </p><p>　　2、現(xiàn)澆板上不要過早上人、堆料、施荷加載，因混凝土澆筑后要有一個硬化過程，才會有強度；在這個過程中，應對混凝土加以保養(yǎng)，不能對混凝

59、土施加任何外力。如果在混凝土尚未有一定強度的情況下，在其上面集中堆放建筑材料或支模立撐，這樣帶給現(xiàn)澆板的不是強度，而是更多的裂縫。因此，必須做到在混凝土強度達到1.2N/mm2以后，才允許在其上踩踏或安裝模板及支架。 </p><p>　　3、嚴格控制板面負筋保護層厚度?，F(xiàn)澆板負筋按設計要求都放在板上面，有梁通過或隔斷時一般放置在梁鋼筋上面或與梁鋼筋綁扎在一起。為了控制好負筋保護層厚度，必須采用Φ10-Φ14的鋼

60、筋馬凳，縱橫間距800mm左右來固定負筋的位置，并用電焊把馬凳與負筋焊牢，使馬凳在混凝土澆筑過程中不移位，保證負筋不下沉，從而有效控制負筋保護層的厚度，不使板負筋保護層過厚而產生裂縫。 </p><p>　　4、嚴格控制好砂、石粒徑及含泥量。現(xiàn)澆板應選用中粗砂，粒徑在0.25-0.5mm之間的石子，砂石含泥量均不得超過1％。如砂、石粒徑過細過小，含泥量過大，都會降低混凝土強度，最終會使混凝土產生裂縫。 </

61、p><p>　　5、在板四角配置一定數(shù)量的角筋，即輻射筋。針對現(xiàn)澆板裂縫多發(fā)生在板角這一現(xiàn)象，在板角四周增設Φ8@200mm，長度為1800mm左右的輻射筋，以此來滿足板角應力的需要，使現(xiàn)澆板產生裂縫的應力作用范圍與輻射筋相一致，從而有效地改觀和控制裂縫的產生。</p><p>　　鋼筋混凝土結構中鋼筋連接綜述</p><p>　　改革開放以來，隨著國民經濟的快速、持久

62、發(fā)展，各種鋼筋混凝土建筑結構大量建造，鋼筋連接技術得到很大的發(fā)展。因此，推廣應用先進的鋼筋連接技術，對于提高工程質量、加快施工速度、提高勞動生產率、降低成本，具有十分重要的意義。</p><p>　　鋼筋連接技術可分為鋼筋焊接和鋼筋機械連接兩大類。鋼筋焊接有6種焊接方法，有的適用于預制廠，有的適用于現(xiàn)場施工，有的兩者都適用。鋼筋機械連接常用有3種方法，主要適用于現(xiàn)場施工。各種方法有其自身特點和不同的適用范圍，并在

63、不斷發(fā)展和改進。在實際生產中，應根據(jù)具體的工作條件、工作環(huán)境和技術要求，選用合適的方法以期達到最佳的綜合效益。</p><p><b>　　1、鋼筋機械連接</b></p><p>　　1.1　徑向擠壓連接</p><p>　　將一個鋼套筒套在兩根帶肋鋼筋的端部，用超高壓液壓設備（擠壓鉗）沿鋼套筒徑向擠壓鋼套管，在擠壓鉗擠壓力作用下，鋼套筒產生

64、塑性變形與鋼筋緊密結合，通過鋼套筒與鋼筋橫肋的咬合，將兩根鋼筋牢固連接在一起。</p><p>　　特點：接頭強度高，性能可靠，能夠承受高應力反復拉壓載荷及疲勞載荷。</p><p>　　操作簡便、施工速度快、節(jié)約能源和材料、綜合經濟效益好，該方法已在工程中大量應用。</p><p>　　適用范圍：適用于Ф18～50mm的Ⅱ、Ⅲ、Ⅳ級帶肋鋼筋（包括焊接性差的鋼筋），

65、相同直徑或不同直徑鋼筋之間的連接。</p><p>　　1.2　軸向擠壓連接</p><p>　　將兩鋼筋安放成對接形式，利用焊接電流通過兩鋼筋接觸點產生塑性區(qū)及均勻的液體金屬層，迅速施加頂鍛力完成的一種壓焊方法。</p><p>　　特點：操作簡單、速度快、無明火作業(yè)、可全天候施工，節(jié)約大量鋼筋和能源。</p><p>　　適用范圍：適用于

66、按一、二級抗震設防要求的鋼筋混凝土結構中Ф20～32mm的Ⅱ、Ⅲ級熱軋帶肋鋼筋現(xiàn)場連接施工。</p><p><b>　　1.3　錐螺紋連接</b></p><p>　　利用錐螺紋能承受拉、壓兩種作用力及自鎖性、密封性好的原理，將鋼筋的連接端加工成錐螺紋，按規(guī)定的力矩值把鋼筋連接成一體的接頭。</p><p>　　利用錐螺紋能承受拉、壓兩種作用

67、力及自鎖性、密封性好的原理，將鋼筋的連接端加工成錐螺紋，按規(guī)定的力矩值把鋼筋連接成一體的接頭。</p><p>　　特點：工藝簡單可以預加工連接速度快同心度好，不受鋼筋含碳量和有無花紋限制等優(yōu)點。</p><p>　　適用范圍：適用于工業(yè)與民用建筑及一般構筑物的混凝土結構中，鋼筋直徑為Ф16～40mm的Ⅱ、Ⅲ級豎向、斜向或水平鋼筋的現(xiàn)場連接施工。</p><p>