Precast concrete wall panels

Top PDF Precast concrete wall panels:

Behavior of Efficient Two Story Precast Concrete Wall Panels.

Behavior of Efficient Two Story Precast Concrete Wall Panels.

17 The author uses a flat solid panel 30 feet wide by 8 feet high and only 5 inches thick. Appropriate material properties were applied to the panel while steel reinforcement was neglected. Self weight was applied to the structure as well as a lateral wind load of 10 psf. The 3D solid model was divided into 240 eight noded rectangular elements. The stresses, strains, and deflections associated with the loading were then analyzed. The author concludes from experience and experimental results that the predicted values follow expected behaviors. Thus the analysis is successful. The author suggests that a design engineer can use the model to analyze the panel and decide on locations and amounts of reinforcement necessary. The author also states that the model is easily modified to examine different parameters for design such as load cases and support locations by changing the input for the model. The author then gives a general analysis procedure. This procedure is a three step process. The first step is data input, the second is a solution step, while the last is the post solution step. The data input step includes setting the geometry of the panel, specifying loads, and defining the elements. The solution step involves the time and cost associated with solving the problem. Finally, the post solution step involves interpreting the data by creating graphs, tables, and plots of the solutions for analysis by the designer. Lastly, the author concludes that finite element modeling is practical for predicting precast concrete panel behavior and that these models can be used in parametric studies.
Show more

150 Read more

Investigation of Grouted Dowel Connection for Precast Concrete Wall Construction

Investigation of Grouted Dowel Connection for Precast Concrete Wall Construction

Full-scale precast concrete wall panels are typically braced for one week. Hence, the focus of this study was on the properties of the grout in the first 7 days. The grout used in this study was a commercially available, pre-packaged, non-shrink grout containing well- graded fine aggregate and fly ash. One 25 kg bag was mixed with 3.75 L of water to achieve a fluid consistency with a specified 7-day compressive strength of 30 MPa, as indicated by the manufacturer. All materials were stored, cast, and cured at ambient laboratory conditions (T = 23 ± 1°C). After one day of curing at ambient conditions, the specimens were moved to a temperature-controlled environmental chamber preset at the specified temperature until the testing date. The internal temperatures of the grout cylinders and pullout specimens were monitored at subfreezing temperatures with probes carefully placed at the center of the cylinders and pullout specimens; temperature readings were taken every 10 minutes for 7 days. The control specimens were maintained at ambient laboratory conditions until testing. Since the fresh grout in this connection is encompassed by the wall panel, it is difficult to continuously moist-cure it in the field. Therefore, to replicate practical applications, the grout was not moist-cured.
Show more

105 Read more

Evaluation of Wall Panels Using Geopolymer Concrete

Evaluation of Wall Panels Using Geopolymer Concrete

ABSTRACT: This Project is done to find compression and flexural properties of Precast Geo polymer Concrete wall panels. Geo polymer precast concrete wall panels in configurations such as load bearing walls, partition walls, window panels and other shapes that provide an attractive, functional and durable facade. Precast wall panels use sandwich construction. Rely on these precast enclosure systems to achieve exceptional results on all-precast, parking garage, steel frame or cast-in-place commercial and institutional structures and buildings. All precast concrete panels are cast in a controlled environment. We can ensure minimal expansion and contraction for superior results every time. This dependability is just one of the reasons why construction professionals choose Green Concrete for the most complex construction projects.
Show more

7 Read more

The structural behaviour of precast lightweight foamed concrete sandwich panel as a load bearing wall

The structural behaviour of precast lightweight foamed concrete sandwich panel as a load bearing wall

Stoll et al., (2004) investigated the effect of weight, strength, stiffness and failure mode of Fiber-Reinforced Composite (FRC) core in composite sandwich construction. In this study, dry fiber and preform foam are used in the molding processes to produce a fiber reinforced composite core panel. An FRC core pre-form was manufactured by cutting a foam board strip which was wrapped by fiber glass fabric around it as shown in Figure 2.3 and consolidating multiple wound strips into sheets as in Figure 2.4. Fiber glass fabric is added to the surfaces of the pre-form and the lay-up is infused with thermoset resin to produce a molded panel as shown in Figure 2.5. The fiberglass used in FRC test panel is E-glass fabric with G6 and G18 facing design. To enable comparisons of FRC cores with other core materials, test panels with 2.5 cm thick foam and balsa cores were molded. An 80 kg/m 3 PVC foam test panel was molded with the same facing design as the G6 test panels, and a nominal 150 kg/m 3 balsa was molded with the same facing design as the G18 test panels. The results of shear strength, stiffness and compressive strength on the FRC core were compared with the results taken from the tests on panels with PVC foam and balsa cores. It is found that the use of FRC cores increased the shear and compressive strength with only minor increase in core density (Table 2.1).
Show more

54 Read more

Study on precast lighweight foamed concrete sandwich panel (PLFP) connection under flexural load

Study on precast lighweight foamed concrete sandwich panel (PLFP) connection under flexural load

The scope of study will focused on experimental work on the design connection of load bearing PLFP panels. The size of the panels is 900mm height,600 mm height and 300mm height with the same 370mm width and 90mm thick. Connection used is vertical connection which uses plane surface type of connection. The connected wall is justified to be under bending situation due to settlements and also beam deflection. Eight panels were used in this experiment with the same type of connection including one panel for pilot and one panel as control with no connection .The material used is foamed concrete with density1700 – 1800 kg/m 3 as for the panel and the in-fill of the connection is normal mortar with have cement-sand ratio of 1:3. The reinforcement bar 4mm diameter and shear connectors 3mm diameter of mild steel used in this experiment. All of the panel were tested under flexure test.
Show more

42 Read more

Thermal Resistance of Two Layers Precast Concrete Sandwich Panels

Thermal Resistance of Two Layers Precast Concrete Sandwich Panels

Abstract—The main difference between normal precast wall and precast sandwich wall panel (PCSP) is the thermal insulation layer which is introduced not only to reduce the weight of the panel but more importantly is to improve the thermal resistance of the panel. Besides the type of insulation material, thermal performance of the sandwich wall panel is also influenced by the arrangement of the shear connector and the contact area between the concrete layers. This approach eliminates the direct transmission path between the two concrete layers at the same time. Hence, this study is conducted to determine the influence of shear connector spacing to the thermal path of PCSPs. A total of four specimens and each size of 500 mm x 500 mm by 150 mm thickness was prepared for the Hot Box Test. The staggered shear connector is spaced at 200 mm, 300mm, 400mm for P2, P3 and P4 specimen, respectively. While the control (P0) have steady shear connector at 200mm spacing. Based on the results, the control specimen achieved the highest thermal conductivity and the lowest is achieved by P4, a panel with shear connector at 400 mm spacing. Hopefully this two layers PCSP will provide to the industry a lighter weight and higher thermal resistance load bearing wall panel in the near future
Show more

5 Read more

The structural behaviour of precast lightweight foamed concrete sandwich panel as a load bearing wall

The structural behaviour of precast lightweight foamed concrete sandwich panel as a load bearing wall

ble foam using a mechanical air-entraining admixture. The product is a cementitious paste of cement and fine sand with micro discrete air cells uniformly distributed throughout the mixture to create a lightweight concrete. The density of the foamed concrete is controlled by the amount of tiny air pockets added into the mixture via foaming process. Lightweight foamed concrete has been used in construction for non-structural building wall panels or as partitions. It is considered as an attractive material because of its lightweight, better thermal properties and ease of construction.
Show more

39 Read more

Affordable Housing Materials and Techniques Santosh Kshirsagar 1, Jayanath Patil1 , Shaila Chaudhari 1, Prof Sachin Kumbhar2

Affordable Housing Materials and Techniques Santosh Kshirsagar 1, Jayanath Patil1 , Shaila Chaudhari 1, Prof Sachin Kumbhar2

After study of different housing materials it is observed that concrete is versatile material and its ingredients are easily available in India and all over the world, for the project work major material is consider as wire mesh concrete, which is used in prefabricated concrete product as cement concrete door and windows frames, prefabricated concrete ventilators, wall panels which is majority used in khandesh are. For this work precast concrete product factories in khandesh area are observed and from that observation one technique which is use in precast concrete compound wall panels is selected as the cost efficient technique for this project work, it is made up of wire mesh concrete techniques, wire mesh of 2-3 mm diameter is used as reinforcement and the thickness of the panels of 5 to 10 cm depending upon its use in different situations, generally 5cm thick wall panels are used in precast compound walls ,use of wire mesh is reduce the cost of normal steel used concrete works. Following figures shows the casting and fixing of precast concrete wall panel pro ducts which are easily available in the khandesh area.
Show more

13 Read more

Test and Finite Element Analysis of Gravity Load Designed Precast Concrete Wall Under Reversed Cyclic Loads

Test and Finite Element Analysis of Gravity Load Designed Precast Concrete Wall Under Reversed Cyclic Loads

However, the above mentioned precast wall details have been mainly designed for gravity load resistance. As the connection details provide low level of difficulty, unless requiring more details, the applicability for low-rise buildings in moderate seismic area is possible. Hence, this research aims to study the seismic performance of the precast concrete bearing wall system for low rise buildings and especially focuses on the connection between precast wall in upper and lower story in Thailand. Two wall panels were tested under cyclic loading. It is noted that, all specimens were only designed for gravity load. In addition, nonlinear finite element analysis was conducted and proposed equation from literature [15] for estimating lateral shear capacity was used to determine the capacity. This study extracts the way to modify the connection appropriately resisting seismic force. If the connections of precast concrete wall have enough ductility for resisting low to moderate seismic force, it will be the solution of the current construction method for residential house. Since precast concrete technique can reduce the construction course, labor course, construction time and waste material at construction site while give the better quality control for construction material. It also reduces the seismic hazard for people who live in risk area.
Show more

16 Read more

The structural performance of precast lightweight foamed concrete panel (PLFP) with double shear connectors

The structural performance of precast lightweight foamed concrete panel (PLFP) with double shear connectors

The development of lightweight, industrialized and sustainable housing system in Malaysia as per modular coordination system is a need of the day. In Malaysia, brickwall is a common wall for use as load bearing wall. However, brickwall is time consuming, require large number of workers, difficult to control the quality and produce high wastage percentage at the construction site. Therefore an alternative precast system is required to replace this traditional system. To encounter demands from the growing population and migration of people to urban areas, new alternative technology is required in the construction industries which can meet demands for higher performance, affordable quality housing and environmental efficient. Current research on precast wall panel only focuses on the performance of solid panel from conventional concrete. These panels are strong but have a weakness such as heavy and not environmental friendly.
Show more

52 Read more

Experimental Investigation of Vertical Connections in Precast Wall Panel Under Shear Load

Experimental Investigation of Vertical Connections in Precast Wall Panel Under Shear Load

Prefabricated concrete shear wall panels are used extensively in high rise construction. Precast concrete structural systems benefit from advantages, such as improved quality of construction, efficient use of materials, reduced construction time, and cost efficiency. In addition, precast concrete allows architects and engineers to perform more innovative designs than traditional cast- in-place concrete design.

6 Read more

Advances in Precast Concrete Sandwich Panels toward Energy Efficient Structural Buildings

Advances in Precast Concrete Sandwich Panels toward Energy Efficient Structural Buildings

In 1987, Zarr [88] introduced a sandwich panel referred to as super-insulated wall panel by using thermal path approach. The panels were designed using timber material which are staggered in framing to increase thermal flow path and break direct thermal bridges between the two sides of the panels. The thermal insulation capacity of the super-insulated timber panels were observed to be three times that of the conventional wood panel. Similar concept was implemented in three-layer PCSP with a total thickness of 279.4 mm by Lee and Pessiki [89]. The panels indicated improved thermal performance by 19.8% compared with the control specimen of direct connection. However, the authors reported that the panel is un-economical due to its excessive thickness and required cumbersome production method leading to prolonged production time. Also, the excessive concrete volume leads to increase weight and cost of materials. In an attempt to improve the challenges aforementioned, the thermal path concept was adopted in a 150 mm thick two-layer super-insulated precast concrete structural sandwich panels (SIPCSSP) by Bida [90]. Three different staggered spacing of shear connectors were tested using hot box test method and verified by FEM model. Despite the conventional steel and concrete used in the panels, the results show improved thermal performance by 117% for 200 mm spacing, 207% for 300 mm spacing and 236% for 400 mm spacing as compared to the direct 200 mm shear connector spacing (control specimen). The results are well within the allowable near zero energy buildings (nZEB) requirements for new and sustainable buildings.
Show more

16 Read more

Review On Stratified Concrete Wall Panels

Review On Stratified Concrete Wall Panels

is a property of the material that enables it to absorb and store thermal energy within its mass. This means that the concrete will absorb heat when the room is hot, store it, and then release it once the internal temperature drops below that of the concrete. This results in cooler feeling rooms in summer and warmer rooms in winter. This means the temperature spikes are removed; interior temperature remains within a comfortable living temperature.The use of precast stratified panel systems offers the opportunity to control the quality of the end product to a very high degree, because the panels are supplied from specialized precasting factories and therefore cast in controlled environment. This fact is very important for stratified concrete specimens, due to the vibration process must be controlled to achieve a correct stratification.The separation is defined as the overwet or overvibratedconcrete.Into horizontal layers with increasingly lighter material toward the top. Water, laitance, mortar, and coarse aggregate will tend to occupy successfully lower position in that order.A layered structure in concrete resulting from placing of successive batches that differ in appearance.
Show more

5 Read more

Structural Behavior of Precast Prestressed Concrete Sandwich Panels Reinforced with CFRP Grid

Structural Behavior of Precast Prestressed Concrete Sandwich Panels Reinforced with CFRP Grid

Three wythe wall panel systems exhibit enhanced thermal behavior due to the increased thermal path from the inner wythe to outer wythe. It should be noted Lee and Pessiki’s (2004) study was only conducted with extruded polystyrene foam. Within this study, Lee and Pessiki (2004) conducted finite elements modeling (FEM) to analyze the thermal predictions of three wythe concrete insulated sandwich panels. They found that using solid elements for modeling concrete and foam while using shell elements for modeling steel plates produced results with 95% accuracy. For this level of accuracy, thermal properties must be known of the concrete, foam core and thermal barriers such as the shear transfer mechanisms. FEM was found to represent thermal performance better than the isothermal plane method and parallel flow method. Isothermal plane method and parallel flow method yielded results within 88% and 58% accuracy, respectively.
Show more

243 Read more

CFRP Grid/Rigid Foam Shear Transfer Mechanism for Precast, Prestressed Concrete Sandwich Wall Panels.

CFRP Grid/Rigid Foam Shear Transfer Mechanism for Precast, Prestressed Concrete Sandwich Wall Panels.

Even at the time of Collins’ article in 1954, it was well known that shear ties were needed to connect the outer concrete wythes together. Collins suggested that a wood fiber filler material could possibly be used without shear connectors, though he noted that most designers chose to include minimum shear ties for all tilt-up construction panels. Examples of shear ties at the time are shown in Figure 2-2. Finally, Collins concluded by mentioning that, “The proposed sandwich wall panel – 33 ft. high, 6 ½ in. thick, with two outer shells 1 ¾ in. thick, the filler of lightweight concrete, and prestressed - would meet the reduced weight requirements, provide excellent insulation and offer one of the best opportunities to date to prestress wall panels economically.” The millions of square feet of sandwich panels produced to date demonstrate the validity of Collins’ statement.
Show more

210 Read more

Use of CFRP Grid as Shear Transfer Mechanism for Precast Concrete Sandwich Wall Panels.

Use of CFRP Grid as Shear Transfer Mechanism for Precast Concrete Sandwich Wall Panels.

The potential of the precast concrete system was utilized in single family home construction as far back as 1938. A single family home was built in the suburbs of Washington, D.C. to demonstrate the concept of precast panels with two inch thick mosaic precast concrete panels as exterior walls. These precast panels were not sandwich panels and provided only the façade of the structure; a wood frame was used to support the panels and to supply the main structure for the home. This construction illustrated the potential savings in labor while aiding in the ease of construction/installation (Early, 1935). Further utilizing this technique, a 1000-family housing development named Forrestal Village was erected in 1951- 1952 at Great Lakes, Illinois. It was the first large scale residential construction project in North America to employ precast concrete sandwich wall panels (Lorman & Wiehle, 1953). Shear connectors in the form of 6” long steel J-pins were used during construction, similar to the pin shown in Figure 2-2(D). These pins were punched through the foam insulation layer into the bottom concrete wythe and the top layer cast on the “J” portion protruding upward. Use of shear connectors became ideal and different variations were used like 4” wide strips of welded wire mesh and also metal shear connectors like the one shown in Figure 2-2(A&B).
Show more

209 Read more

GFRP Shear Grid for Precast, Prestressed Concrete Sandwich Wall Panels.

GFRP Shear Grid for Precast, Prestressed Concrete Sandwich Wall Panels.

At this time ideal sandwich core materials were established. These middle layers were to be materials with low density, relatively high compressive strength, high shear strength, good bonding characteristics, high insulative qualities, and low cost. Available materials at the time were divided into four categories—cellular glass materials and plastic foam, compressed and treated wood fibers in cement, foam concrete, and lightweight concrete— where it was concluded that for the precast industry materials such as cellular glass or compressed wood fibers should be used for the precision-made type of sandwich wall panel. Whereas the lightweight concrete mixes were suggested for the cast-in-place large tilt-up sandwich wall panel in order to achieve economic feasibility. Collins also showed tremendous foresight by suggesting that the ideal sandwich wall panel would be 9.9m high, 165mm thick, with two 45mm thick outer wythes, lightweight concrete filler, and prestressed. He stated that it would provide more competitive weight characteristics, excellent insulation, and one of the best opportunities to prestress wall panels economically. Most sandwich wall panels today are of an impressively similar configuration (Collins, 1954).
Show more

267 Read more

Out of Plane Strength of Hollow Core Concrete Masonry Unit

Out of Plane Strength of Hollow Core Concrete Masonry Unit

ABSTRACT: Precast construction techniques have gained huge popularity in the recent times due to rapid construction, excellent quality control and lesser labor costs and more overall savings. The most advanced typed of precast construction is wall panel construction, which essentially consists of huge concrete panel units cast to the required wall dimensions. However wall panel construction is associated with the requirement of huge machinery for transportation, hoisting and placing operations. The present study proposes a new precast hollow core masonry unit which combines the advantages of precast wall panels, omitting all of its disadvantages. The individual units are smaller in size and are modular based. Hoisting and placing equipments with lower capacity will be sufficient for operation. The proposed system was cast and was experimentally tested by subjecting it to out-of-plane static loads. The results were found to be superior to conventional concrete brick block masonry wall. An FEM model was also developed using NX NASTRAN to study the behavior of the units analytically.
Show more

12 Read more

Impact of Corrosion of Reinforcement in Precast Concrete Construction

Impact of Corrosion of Reinforcement in Precast Concrete Construction

works were inspected by removing the siporex concrete cover to the M.S. reinforcement (figs. 5 & 6). It was found that the reinforcement treated with inertol and ACM (Latex + Cement) coating was showing no signs of corrosion and that the Inertol treatment was intact on bars observed after 1 to 2 years of construction. This treat- ment, therefore, appears to be quite effective in coastal and highly polluted areas like Bombay.

6 Read more

Economical and Structural Feasibility of Concrete Cellular and Solid Blocks in Kurdistan Region

Economical and Structural Feasibility of Concrete Cellular and Solid Blocks in Kurdistan Region

The old Iraqi specification standard (ISS) from 1987 gives directions on how to produce the concrete blocks. ISS was created based on American Society for Testing and Materials (ASTM) Specification of materials Part 16 of year 1986, the British Specification (BS) No. 1364 and No. 2028 of year 1968 and Japanese specification A No. 5406 of year 1976. The load-bearing concrete masonry units part of ISS covers resolutions for Dimensions, Categories and Physical requirements in details. The requirements provide instructions for class (A) block as general use in the internal or external walls which are exposed to moisture or climate changes under or above ground level with variation of any dimension must be no more than ± 3 mm. The physical requirements of cellular concrete blocks with an extraction of average value provided for solid and hollow blocks recommended as a minimum compressive strength of 10 N/mm 2 and maximum water absorption of 12.5%, (Siram, 2012). It is also advised that concrete blocks must not be used before 14 days of their production. Factories which failed complying with these ISS recommendations were fined and their product were removed from the market (ISS, 1987). However, since the release of ISS in 1987 Iraq has gone through two wars and ongoing sectarian war therefore follows up regulation has not been a priority for the market in this country.
Show more

7 Read more

Show all 10000 documents...