土木工程专业毕业设计外文翻译溷凝土

1、roduction and prevention and cure of the crack of skyscraperAlong with the speeding of town house construction step, not a few areas with small residences set up one after another, many inhabitants move continuously into the new residence, their quality to housing request is more and more high, part

2、icularly pay attention to very much to some cracks circumstances which sprinkle building plank to appear now, worry these cracks' aring end will cause insecurity trouble, but in succession to building quality direct the section hurl tell.Such as once the some city develop a company to set up 6 l

3、ayers 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 together building plank is togetherwhole to sprinkle, the plank thick 100 mms, conc

4、rete 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 reinforcing bar cage of the foundation adoption infuses to note a stake.It's small area's turn to complete work in October,2003, finishing construction ac

5、ceptance, didn't discover obvious crack, discover the building plank appears crack when the inhabitant repair, past jointly to quality direct the section hurl tell, through step to see on the spot, 16 houses all exist the depth different crack.The crack width is between the 0.2 mms mms-0.4ses, t

6、he great majority of the crack position is placed in plank four Capes, the dynasty sun is more obvious.Hence, the Superintendent office of quality concerned, sinking to decline quantity and inclination degree to carry on a reexamination to the house first, result all in allow the scope, again look i

7、nto construction diagram paper to also match to request concerning the norm.Owing to above-mentioned circumstance, pass by hard analytical, the confirmation crack reason has the following what time: 1, cause now main reason of sprinkling the plank crack is the constringency of concrete, the concrete

8、 is in the nature the hardening the process, because water evaporates continuously, but the 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 no

9、w should the dint exceed certain limit, certanly will cause to sprinkle plank to open crack now.And the crack part take place much at should the dint more concentrated Cape in the place-plank, but is mutually perpendicular with the Overcast angle line of wall 2, construct too early on the cast-in-pl

10、ace board , add and carry on one's shoulder or back the crack 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 developer , for race

11、 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 post of purpose to trample, carry the material , concentrate on piling up fragment of brick , mortar , template ,etc. Prem

12、ature adding and is carried on one's shoulder or back, has caused the crack of cast-in-place board artificially.3, 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 hydra

13、tion, especially in summer, after the 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 split , result in fracturing finally. Inv

14、estigation find in the majority board corner crack in , tan by the sun towards the front directly the sun. 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 in order to save the land, often take the length of the hou

15、se 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 or exceed should set up interval that expansion joint require , will present the crack too. 5, the board is defeated by the muscle and sun

16、k in the crack produced . In the course of constructing, because 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 bearing capacity of the

17、 board unable to reach the requirement of ones that design, thus cause the production of the crack of board. Effective height, make the bearing capacity of the board unable to reach the requirement of ones that design, thus cause the production of the crack of board. How to prevent and cure the prod

18、uction of the board crack of cast-in-place board, according to the construction experience for many years, offer some following prevention measures, suitable for consulting : 1, Do well cast-in-place board maintain , work , guarantee concrete intensity , prevent and cure important link that crack pr

19、oduce 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 ignored to concrete watered maintenance, on one hand it reduce concrete intensity, on the othe

20、r hand it make concrete to be in the course of hardening too late to supplement the moisture, therefore lack water and produce the crack in a large amount. So do a good job of watering maintenance of concrete , can already reduce the crack that temperature produces , can also reduce the crack that t

21、he concrete shrink and produce . 2, cast-in-place board don't pass 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 . In a situat

22、ion 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, but more cracks. So, must make sure that just allow to trample or install template and suppor

23、t on it after the concrete intensity reaches 1.2N/mm2. 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 to designing requirement through generally put on reinforcing bar of roof beam or

24、stay with reinforcing bar lashing of roof beam cut off ,. For control good to shoulder muscle antiabrasion layer thickness , must adopt 10 - 14 reinforcing bar horse stool, vertical-horizontal interval 800mm come fixed position to shoulder muscle from side to side, and with electric welding horse wi

25、th shoulder muscle weld firm stool, make horse to be stool while the concrete builds non-wiping, guarantee , shoulder muscle sink, control , shoulder muscle thickness of antiabrasion layer effectively , make board shoulder muscle antiabrasion layer cross thick producing cracking. 4, control good san

26、d , stone in a foot-path and mud content strictly. The thick 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 big, will reduce conc

27、rete intensity, will make the concrete produce the crack finally.5, dispose certain amounts of angle muscles in four corners of the board , radiate the muscle . Take place in board corner phenomenon this more to cast-in-place board crack, corner set up all around in boardThe length radiates the musc

28、le for about 1800mm, so as to meet demands of angle stress of the board, the stress sphere of action of making the cast-in-place board produce the crack conforms with radiation muscle, thus change and control the production of the crack effectivelyforced concrete structure reinforced with an overvie

29、wReinSince 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 has been great. Therefore, to promote the use of advanced technology reinforced connecting to improve project

30、quality and speed up the pace of construction, improve labor productivity, reduce costs, and is of great significance. 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

31、 some apply 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. Ways has its own characteristics and different application, and in the con

32、tinuous development and improvement. In actual production, should be based on specific conditions of work, working environment and technical requirements, the choice of suitable methods to achieve the best overall efficiency.1、 steel mechanical link 1.1 radial squeeze linkWill be a steel sleeve in t

33、wo 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 steel sleeve plasticity deformation closely integrated with reinforced through reinforced steel sl

34、eeve and Wang Liang's Position will be two solid steel bars linkedCharacteristic: Connect intensity to be high, performance reliable, can bear high stress draw and pigeonhole the load and tired load repeatedly.Easy and simple to handle, construction fast, save energy and material, comprehensive

35、economy profitable, this method has been already a large amount of application in the project.Applicable scope : Suitable for , , grade reinforcing bar (including welding bad reinforcing bar ) with ribbing of 18- 50mm, connection between the same diameter or different diameters reinforcing bar .1.2

36、must squeeze linkExtruders used in the covers, reinforced axis along the cold metal sleeve squeeze dedicated to insert sleeve Lane two hot rolling steel drums into a highly integrated mechanical linking methods.Characteristic: Easy to operate and joining fast and not having flame homework , can cons

37、truct for 24 hours , save a large number of reinforcing bars and energy.Applicable scope : Suitable for , set up according to first and second class antidetonation requirement -proof armored concrete structure , grade reinforcing bar with ribbing of hot rolling of 20- 32mm join and construct live.1.

38、3 cone thread connectingUsing 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 connecting steel bars.Characteristic: Simple , all right pre

39、paratory cut of the craft , connecting fast, concentricity is good, have pattern person who restrain from advantage reinforcing bar carbon content.Applicable scope : Suitable for the concrete structure of the industry , civil building and general structures, reinforcing bar diameter is for for the t

40、he 16- 40mm one , grade verticality, it is the oblique to or reinforcing bars horizontal join construct live. conclusionsThese are now commonly used to connect steel synthesis methods, which links technology in the United States, Britain, Japan and other countries are widely used. There are differen

41、t ways to connect their different characteristics and scope of the actual construction of production depending on the specific project choose a suitable method of connecting to achieve both energy conservation and saving time limit for a project ends.References1 、construction manual write the group.

42、 Construction manual. Beijing: China Construction Industry Press, 1992.2 、JGJ107-96 reinforcing bar machinery connects the common technical regulation 3 GB 1499-91 The armored concrete uses the reinforcing bar. 4 、GB with ribbing of hot rolling 13013-91 The armored concrete uses the round reinforcin

43、g bar of hot calendaring.现浇楼板裂缝的产生与防治随着城市住宅建设步伐的加快，不少住宅小区相继建成，许多住户陆续搬进新居，他们对住房的质量要求越来越高，尤其对一些现浇楼板出现的裂缝情况非常关注，担心这些裂缝最终会引发不安全事故，而纷纷向建筑质量监督部门投诉。 如某市一开发商共建6层楼住宅16幢，建筑面积约10万平方米，砖混结构，初装修，一梯二户用砖墙分隔，每层设有圈梁同楼板整浇，板厚100mm，混凝土标号为C20，房屋长约80-90m之间，不设伸缩缝，底层为2.2m车库层，基础采用C20钢筋笼灌注桩。该小区于2003年10月完工，竣工验收时，未发现明显裂缝，在住户装修时

44、，发现楼板有裂缝出现，故联名向质量监督部门投诉，经实地踏看，16幢房屋均存在深浅不一的裂缝。裂缝宽度在0.2mm-0.4mm之间，裂缝位置绝大多数处在板四角，朝阳处更为明显。于是，质监部门组织有关单位，首先对房屋沉降量和倾斜度进行复查，结果都在允许范围内，再查看施工图纸也符合有关规范要求。鉴于上述情况，经过认真分析，确认裂缝原因有以下几点： 1、引起现浇板裂缝的主要原因是混凝土的收缩，因为混凝土在自然硬化过程中，由于水份不断蒸发，而体积渐渐收缩，但板四周受支座的约束，不能自由伸缩，所以当混凝土的收缩所引起现浇板的约束应力超过一定限度时，势必引发现浇板开裂。而且裂缝部位多发生在应力比较集中的地方

45、板角处，却与墙阴角线相垂直。 2、现浇板上过早施工，加荷引起的裂缝。混凝土结构工程施工质量验收规范规定，混凝土强度达到1.2N/mm2前，不得在其上踩踏或安装模板及支架。但开发商为了抢时间，赶进度，在刚浇好的现浇板上或混凝土尚处在初凝和终凝阶段，就任意踩踏，搬运材料，集中堆放砖块、砂浆、模板等。过早的加荷，人为地造成了现浇板裂缝。 3、温度变化引起的裂缝。大家知道，水泥在常温下具有凝结硬化快，水化热大等特点，尤其在夏天，混凝土浇筑后，水化热释放量大，混凝土在高温下，得不到及时浇水养护，而失水收缩，使混凝土发生干裂，最终导致开裂。调查中发现，居多板角裂缝都处在遭受太阳直接曝晒的朝阳面。 4、房屋

46、过长未设置必要的伸缩缝，也是导致裂缝的原因。开发商为了节省土地，往往不顾及房屋长度，使房屋整体过长，也不设置伸缩缝，由于缺少必要的伸缩缝，当房屋的自由伸缩度达到或超过应设置伸缩缝要求的间距时，也会出现裂缝。 5、板负筋下沉产生的裂缝。在施工过程中，由于施工人员野蛮操作，任意踩踏钢筋，致使负筋下陷，保护层过大，减少了板截面的有效高度，使板的承载能力达不到设计的要求，从而导致板裂缝的产生。 如何防治现浇板板裂缝的产生，根据多年的施工经验，提供以下一些防治措施，可供参考： 1、认真做好现浇板养护工作，是保证混凝土强度、防治裂缝产生的重要环节之一。规范规定，常温下混凝土浇筑后12小时内，必须覆盖保温养护，普通水泥不少于7天，如果忽视对混凝土的浇水养护，一方面会降低混凝土强度，另一方面会使混凝土在硬化过程中来不及补充水分，因而大量缺水而产生裂缝。所以做好混凝土的浇水养护，既可减少温度产生的裂缝，也可降低混凝土收缩而产生的裂缝。 2、现浇板上不要过早上人、堆料、施荷加载，因混凝土浇筑后要有一个硬化过程，才