dnfsdd814

0

N/A

27-10-21

2 Látták




Structural behavior of precast concrete wall panels due to dynamic load: A review

    The rapid population growth and urbanization have made a massive demand for the shelter

and construction materials. Masonry walls are the major component in the housing sector and

it has brittle characteristics and exhibit poor performance against the uncertain loads.

Further, the structure requires heavier sections for carrying the dead weight of masonry

walls. The present investigations are carried out to develop a simple, lightweight and cost

effective technology for replacing the existing wall systems. The lightweight concrete is

developed for the construction of

cement wall panel
. The EPS (Expanded Polystyrene) beads of 3 mm diameter size are

mixed with concrete and developed a lightweight concrete with a density 9 kN/m3. The

lightweight sandwich panel is cast with a lightweight concrete inner core and ferrocement

outer skins. This lightweight wall panel is tested for in-plane compression loading. A

nonlinear finite element analysis with damaged plasticity model is carried out with both

material and geometrical nonlinearities. The experimental and analytical results were

compared. The finite element study predicted the ultimate load carrying capacity of the

sandwich panel with reasonable accuracy. The present study showed that the lightweight

concrete is well suitable for the lightweight sandwich wall panels.
    Architectural precast concrete wall panels that act as loadbearing elements in a

building are both a structurally efficient and economical means o f transferring floor and

roof loads through the structure  and into the foundation. In many cases, this

integration can also simplify construction and reduce costs. This article presents the many

benefit s that ca n be derived from using loadbearing architectural precast concrete walls

in buildings. Discussed herein are the various shapes and sizes of wall pane ls, major

design considerations, and when loadbearing or shear wall units should be the  first

design choice. The role o f connections, shear walls, and the use of precast concrete as

forms for cast-in-place concrete is explained. In general, the design methods and

techniques presented in  this article apply to buildings in both seismic and non-

seismic areas. The latter part of this article shows how these design principles can be

applied in practice in a variety of buildings. These examples illustrate the use of window

wall panels, spandrels, and solid or sandwich wall panels as the loadbearing wall members.

When all the advantages of using architectural precast concrete as loadbearing walls are

added up, it  makes good sense to use this structural form in building

applications. 
    An experimental study has been carried out to determine the strength and behaviour of

bamboo-reinforced concrete wood texture cement wall panel under one-way in-plane

action. Three full-scale bamboo-reinforced concrete wall panels were tested to fail under a

uniformly distributed load applied at an eccentricity of t/6. Slenderness ratio of all wall

panels was kept constant as 25 with varying aspect ratio and thinness ratio. The influence

of aspect ratio and thinness ratio on the ultimate strength and behaviour of wall panel was

studied. The aspect ratio of wall panels considered includes 1, 1.204 and 1.515, and

thinness ratio of wall panels includes 16.5, 20.75 and 25. Based on the study, an empirical

equation for predicting the ultimate load of bamboo-reinforced concrete wall panel was

proposed.
    The effect of the earthquake resulted in the destruction of infrastructure, especially

residential buildings. The construction of decent housing with an adequate level of

security is a demand. Generally, the most severe damage when an earthquake occurs is wall

collapse of the houses. The precast panel wall is an alternative solution in answering the

needs of post-earthquake housing development, because of the fast construction time and

high calculation accuracy. The behavior of structural precast concrete



split rock surface wall panels
designed improperly instead of following the standard

or regulations will likely encounter a poor performance during an earthquake compared to

those designed in accordance with the standards. The purpose of the present study is to

compile the findings from previous studies of precast concrete panel walls, especially

their performances in handling earthquake load. It reveals that the stability, especially

in ductility, affects the performance of precast concrete panel walls. In this study, the

walls of precast concrete panels are made in half scale and given dynamic loads to simulate

earthquake forces. This review is expected to provide guideline of similar subsequent

research.
    It’s no wonder demand for precast is rising, especially considering the numerous

benefits structural precast panels offer — from quick installation to fire resistance.
    1. Thermal insulation
    All elements of a well-engineered structural precast panel work together to provide a

high level of insulation. Manufacturers often use a combination of concrete and EPS foam

that maximizes the foam in the concrete piece, increasing insulation capabilities. A

building constructed of structural precast panels may reduce energy consumption by as much

as 30%.
    2. Sustainable materials
    Quite simply, a building made with structural precast panels will consume less energy,

but an idea that should be at the heart of any sustainability conversation is product life.

The use of concrete dates back to Roman times and its durability is still on display all

across Europe. That raw, ancient building material has remained virtually unchanged for

thousands of years. Many of the materials used in precast concrete are, as a rule, locally

sourced, including the cement, the coarse and fine aggregates, and the steel.
    3. Long-term viability and flexibility
    Structural precast allows for a very modular building envelope. As business

requirements change and needs evolve, an existing precast building has the flexibility to

be expanded and modified. With structural precast concrete panels, you can add or remove

pedestrian doors and dock doors, incorporate daylighting options, and even remove 75% of a

wall. And due to its modular design, total repurposing of a precast building is entirely

possible; churches can become car dealerships, warehouses can become micro-breweries… the

options are only limited by a property owner’s imagination.
    4. Quick installation
    Speed is a critical hallmark of structural precast construction. “With precast panels,

you can establish a larger completed footprint in a shorter amount of time,” says George

Miks, director of engineering.“If you think of a masonry wall, what they send out to the

site are a bunch of blocks that have to be assembled and constructed out in the field.”

When structural precast panels arrive at a job site, the pieces are ready to install. If

things go smoothly out in the field, an experienced crew can install 20 to 30, 12-foot

panels in a day.
    5. Load-bearing capabilities and wind resistance
    Structural precast concrete panels are comprised of high-strength concrete and

prestressed steel strand. It’s relatively routine for precast concrete wall panels have a

compressive strength of approximately 7,000 PSI. You can apply loads in excess of 100,000

pounds to the panels, Miks says. “When you build steel buildings, for instance, you have

to put up perimeter beams and columns and then put steel skin against it. All of that steel

has to support those enclosure panels,” Miks says. “With a structural precast wall

system, you don’t need any of those perimeter beams and columns. You can just tip up the

panel and have the roof steel members themselves attach to the precast. That also means you

’ll be spending less on steel.” Precast also stands up to Mother Nature’s wrath,

shrugging off tornadoes, flying projectiles and winds up to 250 miles per hour.
    6. Fire and sound ratings
    Concrete is obviously an effective barrier for fire; it simply doesn’t burn well.

Precast concrete thin cement rammed earth wall panels are capable of providing

a two- to four-hour fire rating. Precast walls also stay intact even in hot chemical fires.

Warehouses often use precast wall panels as dividers to protect goods on the other side of

fire-prone areas. “The more delay you can create from one side to the other, the better

chance of getting people out safely without incident and also the higher probability of

protecting goods and services,” Miks says.
    Constructing a commercial structure is a huge undertaking and a significant investment.

Whether you’re charged with the growth of a company, serving your community or building a

legacy of your own, precast construction is a solid, responsible option said Miks.
    In this paper, an optimization-based design model of precast concrete

cement rustic decoration wall panels for a building facade is presented.

The key concept is an integrated model that can concurrently handle all of the related

design and construction disciplines in the decision making process. The integrated model is

decomposed hierarchically into several subproblems, thus a multilevel multiobjective

optimization problem is obtained. Besides the multilevel aspect, the model presented can

also handle knowledge-based requirements which are in general difficult to deal with by

conventional hill-climbing optimization schemes. A solution procedure to solve this model

is developed and applied to an example of PCWP for a four-story building facade.

Megosztás




Ingyenes hirdetés / Álláshirdetés feladása, regisztráció nélkül!
Álláshirdetések, Ingatlanok, Eladó járművek, IT, informatika, Egyéb hirdetések, Sporteszközök