Pre-cast and Pre-Fabrication Construction PDF

C IV C M 0 4 16 ADVANCE C O N S T R U C T IO N M E T H O D S A N D E Q U IP M E N T PRE-CAST AND PREFABRICATED CONSTRUCTION ENGR. LAWRENCE A. PASCUAL PLANNING, ANALYSIS, A N D DESIGN CONSIDERATIONS DESIGN OF PRECAST STRUCTURES 1.PRECAST M E M B E R S A R E DESIGNED TO WITHST...

C IV C M 0 4 16 ADVANCE C O N S T R U C T IO N M E T H O D S A N D E Q U IP M E N T PRE-CAST AND PREFABRICATED CONSTRUCTION ENGR. LAWRENCE A. PASCUAL PLANNING, ANALYSIS, A N D DESIGN CONSIDERATIONS DESIGN OF PRECAST STRUCTURES 1.PRECAST M E M B E R S A R E DESIGNED TO WITHSTAND ALL POSSIBLE LOADS AT ALL STAGES, from storage to jointing, as well as potential loads during the course of a building's lifespan. 2. PLANNING FOR ALL POTENTIAL LOADS THAT MIGHT BE PLACED O N JOINTS A N D CONNECTIONS PRECAST AND PREFABRICATED E XAM P LE S OF PRECAST A N D PREFABRICATED CONSTRUCTION Produced in Factories Transported to Site Assembled at Site P A R T IA L O R C O M P L E T E M A T E R IA L S A V IN G S IN C R E A S E D W O R K M A N S H IP A C C U R A C Y LE SSEN ED N EED FO R LA B O R F A S T E R C O N S T R U C T IO N P E R IO D IN D E P E N D E N T O F R O U G H W E A T H E R L O W E R C O S T O F M A IN T E N A N C E C O N C R E T IN G C A N P R O C E E D W IT H O U T IN T E R R U P T IO N P R E C A S T INSTALLATION W A T E R P R OOF I NG MECHANICAL, ELECTRICAL A N D P L U MB I NG FITTINGS FIRE RATING FINISHES PRECAST IINSTALL ATIION S E Q U E N C IN G O F C O N S T R U C T IO N T E C H N IQ U E F O R O F F E R IN G A N D IN S T A L L A T IO N P R O C E D U R E S T E M P O R A R Y A S S IS T A N C E Based on their location n u mbe r and tags, Prior to stabilization, elements should be precast elements should be identified supported temporarily PRECAST IINSTALL ATIION IN S T A L L A T IO N T O L E R A N C E S H A N D L IN G A N D R IG G IN G Codal provisions should serve as the R E Q U IR E M E N T S foundation for installation tolerances, and Before lifting, elements should be examined for design considerations should be m a d e very handling stresses, and the cranes should have transparent. enough lifting power to handle the precast panels. WATERPROOFIING External joints mu s t be sealed with baker rods and sealants after being filled with grout MECHANIICALL,, ELLECTRIICALL AND PL UMBIING FIITTIINGS Mechanical, electrical and p l umb i ng fittings shall be kept open or concealed as per the requirements Before casting, the conduits and electrical boxes must be installed and fixed in the molds Provision of National Building Code for firefighting systems  Fixing electrical boxes and conduits Laying Conduits on Slab Pl umb i ng FIIRE RATIING Precast concrete must be designed for fire resistance in accordance with prescribed standards FIINIISHES Precast concrete can be produced in a variety of shapes, colors, textures, and finishes Rebating, Grooving, Surface coatings, cement-based renders, oxide coloring, and other surface treatments are required CO N SU LTANTS A N D THE P R E C A S T M E T H O D ARCHITECTURAL CONSIDERATIONS STRUCTURAL CONSIDERATIONS E C O N O M I C A L A N D ECOLOGICAL CONSIDERATIONS RISK A N D H E ALTH A S S E S S ME N T IN DESIGN CONSIDERATIONS CONSULTANTS AND PREC AST METHOD NUM EROUS C R IT E R IA D E T E R M IN E W H E TH E R E M P L O Y IN G PRECA ST C O N C R E T E P IE C E S IN A P R O J E C T IS F E A S IB L E. T H E F O L L O W IN G F A C T O R S M UST BE TA K E N IN T O ACCOUNT AS TH E A R C H IT E C T , S T R U C T U R A L E N G IN E E R , D E V E L O P E R /C L IE N T ,A N D P E R H A P S TH E C O N TR A C TO R ON W H E TH E R TO U S E TH E P R E C A S T M E TH O D : TYPE OF BUILDING For repetitive designs with constant spans and floor heights, the precast technique is the most practical Precast concrete cladding components may be used in conjunction with natural stone or tile cladding under similar circumstances S CAL E OF THE PROJECT A high n u mbe r of similar or nearly similar elements will reduce the cost of m o l d per element since the investment in the molds for the casting of elements is distributed on the n u mbe r of elements cast SITE LOCATION AND LOCAL CONDITIONS The possibilities for organizing the precast me th o d in terms of production, storage, and construction will be determined by the site's location, size, and accessibility All components mu s t be delivered on transporters and immediately raised to the construction using the "just-in- time" m e t h o d wh e n the available free area on the site is too little for production or even storage of the parts ECONOMY Precast element construction estimates and budgets can be calculated using labor and material costs in cooperation with precast manufacturers ARCHITECTURAL CONSIDERATIONS B U IL D IN G D E S IG N BA SED ON E S T H E T IC AND P R A C T IC A L C O N S ID E R A T IO N S IS T H E A R T A N D S C IE N C E O F A R C H IT E C T U R E. P L A N N IN G , M A S S IN G , S U R F A C E , P R O P O R T IO N S , A N D T H E U S E O F S U IT A B L E M A T E R IA L S A R E A L L C O M B IN E D T O P R O V ID E A M O D E R N V IS U A L L A N G U A G E T H A T IS A E S T H E T IC A L L Y A C C E P T A B L E. PLANNING The architectural planning and layout must be directed by a modular set of grids with uniform and standardized dimensions that have been analyzed and selected with relation to the programme and purpose of the development when the first decision to employ precast construction or cladding is made MASSING Precast concrete panels in some form will be employed in a development, and the massing selected by the architects will define the complexity and variety of features needed Simple geometric forms work well as precast components and can be assembled into an organic structure with particular design balcony features, stairs, and lift towers connecting th e m S URF ACE The panels' contours or grooves mi gh t accentuate horizontal or vertical lines, an d the joints can be incorporated into designs or drawn attention to as a unique element ARCHITECTURAL P R E CAS T CLADDING Precast elements' exterior claddings and interior non-load- bearing walls are essentially a finishing touch; they are not intended to be a part of the building's structural structure Special consideration mu s t be given to the fixing method, tolerances, and waterproofing of joints wh e n designing precast cladding WATERPROOFING Externally the joints must be able to withstand heavy rain in combination with strong winds w h i c h means that water on some occasions is running upwards. The inner part of external joints must be wind-tight to minimize the pressure STRUCTURAL CONSIDERATIONS A P R E F A B C O N S T R U C T IO N T Y P IC A L L Y N E C E S S IT A T E S A H IG H L E V E L O F D IM E N S IO N R E P E T IT IO N. IN M A N Y IN S T A N C E S , T H IS H A S A L R E A D Y BEEN A C C O M P L IS H E D ; F O R IN S T A N C E , IN ONE P R O J E C T, TH E L E N G T H S B E T W E E N C O L U M N S A N D S T O R E Y H E IG H T S A R E B O T H E Q U A L. IF N O T , A F E W M IN O R M O D IF IC A T IO N S T O M E A S U R E M E N T S T H A T S H O U L D N O T D IF F E R A R E R E Q U IR E D. C O O R D IN A T IN G O N A M O D U L A R O R D IM E N S IO N A L L E V E L IS W H A T T H IS IS A D V A N T A G E S AND CONSTRAINTS Higher construction speed with increased productivity and greater quality are only a few benefits of prefabrication. A prefabricated external wall or cladding typically allows the architect the option for n e w shapes, different surfaces, and other colors Less diversity in a project could be a constraint because a high repetition factor leads to a better economy. Additionally, precasting curving facades and cantilevered features may be more complex INTERGRATED DESIGN CONCEPT It is crucial to understand what components are available, whether the precaster can contribute to the design of joints and components, and whether the contractor has the appropriate expertise to handle prefabricated components DISTRIBUTION OF P RECAS T DESIGN RESPONSIBILITY Using the so-called integrated design approach, the precast design process mu s t be carried out in close collaboration between the architect, the engineers, the prefab maker, and the contractor Many diverse elements, including walls, columns, beams, slabs, staircases, and balconies, will be included in a precast project. Some of these components, such as design charts for vertical loads, will inevitably be created by the precaster or are already a part of a standardized production that is specified in catalogs ECONOMICAL AND ECOLOGICAL CONSIDERATIONS INCREASE IN COSTS In comparison to a comparable construction cast in-situ, the amou n t of concrete used in the construction will often be higher REDUCTION IN COSTS Precast construction has lower labor costs. According to experience, producing one ton of cast concrete elements takes three to four laborers' hours. O n location, each compon e n t resembles around three m a n hours of erection effortconnecting th e m ECOLOGY Evaluation of the total energy consu mption of various buildings, building materials, an d production techniques is n o w natural and visible due to environmental concerns Companies mus t get prepared for the so-called "green accounts" required by several countries The construction industry n o w has access to handbooks containing energy statistics, allowing designers to assess the effects of selecting alternative materials on energy consumption RISK AND HEALTH AS S E S S M E NT Each compon e n t must be designed with the proper end conditions and stresses in consideration at different phases of construction Wh e n designing, appropriate safety measures mu s t be imple me n te d Every load-bearing compon e n t at the building's corners needs to be restrained The design of prefabricated construction mus t take into account the possibility of gas or other explosions, wh ich could obliterate significant structural components and cause the structure to gradually collapse It is essential to mak e sure that any localized damage to a structure does not spread to other areas far from the place of accident and that the structure's general stability is not compromised RISK AND HEALTH AS S E S S M E NT The designer mus t keep a close line of commu n i cati on open with the builder or contractor regarding all areas of erection that have an i mpact on the structural design Construction-related failures seem to fall into one of two categories Pack-of-Cards Collapse: In this kind of failure, the absence of restraints like shear walls, cladding, or partitions suggests that the building was unstable wh e n it was being built Situational Collapse: One element collapses during erection and hits another element be low it in this kind of failure. As a result of the lower element's connections collapsing beneath the weight of the upper element —both static and dy n amic —a series of subsequent collapses is set off MATERIALS, MOULDS & MODULAR COORDINATION & STANDARDIZATION.  What is MOULD in construction? A mould, mold, moulding, or moldin g is a casing formed by a rigid frame of wood, plastic, or metal, in which liquid concrete or other pliable material is poured thus giving it a definite design and shape. Sustainable Architecture Primer What is the difference between Pre-cast and Site cast moulds? Precast mou l ds are designed and manufactured in a controlled environment before they are transported to their desired location for installation. Whereas site cast mou lds are developed in site.  ADVANTAGES OF PRE-CAST MOULDS OVER SITE CAST MOULDS V E R S A T IL IT Y H IG H Q U A L IT Y E F F IC IE N C Y A F F O R D A B IL IT Y E N V IR O N M E N T F R IE N D L Y DECREA SED USE OF M A N P OW ER S TR E N G TH S T R U C T U R A L R E IN F O R C E M E N T Sustainable Architecture Primer  TYPES OF MOULDS BASED ON MATERIALS USED Plastic mould Rubber mould Wood mould Steel mould Aluminum mould MOULDS TREATMENT In using m o u l d paints there are three salient points to be remembered: The paint system must be compatible with the substrate onto w h i c h it is to be applied. The paint shall always be pigmented as the pigment contributes more to the lifetime than the type of paint in wh i ch it is placed. Glossy smooth surfaces should never be used as they promote hydration staining. MOULD RELEASE AGENTS There are five basic groups of release agents: (1) Non- emulsifiable mach i n e oils. (2) Emulsifiable oils giving oil- in-water phased systems (miscible with water). (3) Mou l d creams from water-in-oil phases (immiscible with water). (4) Metallic stearates and those of similar form and k n own as chemical release agents. (5) Lanolin creams.  OTHER MATERIALS CEMENT The most c o m m o n cements used are ordinary and rapid-hardening Portland (including white), sulphate- resisting and high alumina cement. AGGREGATES The ideal shape of a coarse aggregate is rounded, angular and approximately cubic These fall into two main types, each with several sub-groups: Natural Aggregates: Flint Volcanic (granites, basalts, feldspars, etc.) Sandstone Limestone (sedimentary, oolitic, etc.) Marble (calcite) Barytes Natural sands (siliceous mainly, river, dune, wadi, marine) Perlite Vermiculite Synthetic Aggregates: Sintered pulverised fuel ash Expanded shale Expanded slate Expanded clay Foame d slag Crushed bricks Calcined flint Iron Expanded plastics Reconstituted concrete JOINTS IN PRE-CAST & PREFABRICATED CONSTRUCTIONS & CURING TECHNIQUES The connections and joints of precast constructions — w h i c h also act as means of load transfer —ascertain both their stability and strength. What is a JOINT? It f u n c t i o n s t o p r o v i d e p h y s i c a l s e p a r a t i o n b e t w e e n t h e c o m p o n e n t s o f th e st ru c t u re A jo i n t i s w h e re m e m b e rs o r c o m p o n e n t s o f a c o n st ru c t i o n com e tog eth er. A t t h e jo i n t , fo rc e s a re t a k e n p l a c e , su c h a s c o m p re ssi o n , t e n si o n , sh ear etc. A jo i n t c o u l d b e i n c l i n e d , ve rt i c a l , o r h o ri z o n t a l.  What is a CONNEC T I ON? A c o n n e c t i o n i s a n a rra n g e m e n t o r a sse m b l y o f a d ja c e n t m e m b e rs o r e l e m e n t s fro m t h e c o m p o n e n t s o f a jo i n t. A c o n n ec tio n is b u ilt to w ith st an d th e im p ac t o f fo rc es an d m o m en ts. PURPOSE of joints and connections IN P R E C A S T C O N S T R U C T IO N To transmit forces between structural components To provide overall stability To provide strength to the structure To prevent external leakages To resist unpredictable loads due to fire, i mpact & explosion  REQUIIREMENTS for connections of joints IN P R E C A S T C O N S T R U C T IO N STRE NGTH F IR E R E S IS T A N C E R E S IS T A N C E T O Th e c o n n e c t i o n m u st b e ab l e t o A connection w hich could be C H A N G E IN V O L U M E w i t h st an d the fo rc e s t h a t are vu l n erab l e b y fi re ex p o su re sh o u l d b e As a resu l t of the com b ined a p p l i e d t o i t o ve r i t s l i fe t i m e. sealed o ff. sh o rt e n i n g c au se d by c reep , sh ri n k ag e, and tem p eratu re r e d u c t i o n , t e n si l e st re sse s m u st b e a c c o u n t e d fo r. D U C T IL IT Y D U R A B IL IT Y Th e c o n n e c t i o n 's cap acity to A c o n n e c t i o n 's e x p o se d se c t i o n w it h st an d sig n ific an t d efo rm at io n s need s rou tin e m ainten anc e and w it h o u t failin g. in sp e c t io n. C CLLA ASSS SIIFFIIC CAATTIIO ONN of joints B A S E D O N M E T H O D O F C O N N E C T IO N D R Y J O IN T W E T J O IN T Joint accomplishe d by simply joint that needs ce me n t casting placing of two me mbe rs by as well as grouting and means of fastening. concreting materials.  TYPES OF CONNECTIONS IN A PREFABRICATED CONSTRUCTION TYPES OF CONNECTIONS COLUMN TO FOUNDATION For this kind of connection, you have to consider wha t kind of an i m pa ct the c ol u m n connection can ma ke on your overall building process. There are three kinds of the c ol u m n to foundation connections: Socketed connection Bolted or base plate connection Mechanical splice connections TYPES OF CONNECTIONS COLUMN TO FOUNDATION TYPES OF CONNECTIONS WALL P A NEL TO FOUNDATION These types of connections are used to tie the load- bearing walls to the foundation. Any connection joining a wall panel to a foundation wall or a continuous footing should provide a means of leveling and aligning the panel. The attachment m e t h od also should be capable of accepting the base shear in any direction. The capacities of these connections are the e m b e d edge distances and other design assumptions that should satisfy production and design standards. TYPES OF CONNECTIONS WALL P A NEL TO FOUNDATION TYPES OF CONNECTIONS B E A M TO COLUMN Beam-to-c o l u m n connections provide moment - resistant connections between beams and column s at the corners of frames or a m o m e n t resisting connection to elongate beams. The connection configuration and response including strength, rotational stiffness and ductility affect buildings in several ways for this dry and wet connections are possible in the b e a m to c ol u m n connection. TYPES OF CONNECTIONS B E A M TO COLUMN TYPES OF CONNECTIONS COLUMN TO COLUMN Co l u m n to c o l u m n connection’s primary function is to keep panels from b owi ng and/ or to transfer vertical shear force between panels. The connection is durable against corrosion due to the coverage for grout over the connection. This type connection involves the use of splice connection and anchor bolts. Splice connection Anchor bolt connection TYPES OF CONNECTIONS COLUMN TO COLUMN TYPES OF CONNECTIONS SLAB TO B E A M A m o n g all precast connections, the precast slab to b e a m connection is considered a vital one as the horizontal load is transferred to the vertical load resisting structural elements by the diaphragm action.The slab and beam should be connected properly and detailed sufficiently so that the transfer of loads occur smoothly to ensure integrity and continuity in the structure. TYPES OF CONNECTIONS SLAB TO B E A M TYPES OF CONNECTIONS WALL TO WALL Wall to wall connection creates a connection between tw o precast walls. Construction of precast walls are very rigid since the element are inherently stiff to begin with. Therefore, it is important to detail the connections in such a way to ensure robustness in the event of a natural disaster such as earthquake and absorb its energy to avoid complete collapse. Bolted Connection Welded Connection Anchor/Dowel Connection TYPES OF CONNECTIONS WALL TO WALL COMMONLY USED CONNECTIONS AND JOINTING TECHNIQUES W E L D IN G O F O V E R L A P P IN G R E IN F O R C E D C LE A TS O R R E IN F O R C E M E N T C O N C R E T E T IE S P R O J E C T IN G BARS A LL A R O U N D A S TE E L SLA B COMMONLY USED CONNECTIONS AND JOINTING TECHNIQUES PRE- E P O X Y G R O U T IN G C E M E N T O R L IM E S T R E S S IN G G R O U T W IT H N O N - S H R IN K A D D IT IV E COMMONLY USED CONNECTIONS AND JOINTING TECHNIQUES P O LYM E R R E IN F O R C E M E N T C O M B IN A T IO N O F SLU R R Y C O U P LE R TH E A B O V E G R O U T IN G A T D O W E LC A S T B O LTS A N D N U TS C O N N E C T IO N ISSUES WITH JOINTS A N D CONNECTIONS Adequate number of joints Joints must have adequate should be provided to transfer strength to transfer gravity and the forces. lateral load between precast elements. The joints and connection between core structure and If joints and connections are not components should be strong well finished and accomplished, enough to transfer different it will result in leakage. kinds of loads. E N D OF PRESENTATION