Showing posts with label BP Composites. Show all posts
Showing posts with label BP Composites. Show all posts

Thursday, 17 July 2014

Three things would be Very Careful While lifting Anchors. Origin, Magnitude and Distribution of Load


Lifting anchors are loaded by the self weight of the concrete element, by forces due to adhesion and form friction and by dynamic actions due to acceleration.
The self weight of the precast concrete element can be calculated using a specific gravity of 23 to 25 kN/m3 for normal weight concrete, depending on the percentage of reinforcement. Mostly this value is already known from the static calculation.

Inertia forces act when the element is accelerated or decelerated by the lifting equipment. These forces must also be transferred by the lifting anchors. The size of the inertia forces scatters between 5 and 50 % of the elements weight depending on the type of crane and the ratio between the weight of the element and the capacity of the crane. Under normal conditions it should be conservative to calculate inertia forces with 30 % of the self weight . Additional considerations have to be made for special situations like transport of elements through rough terrain, for example with an excavator. Inertia forces up to 300 % of the self weight can be expected in such cases.
When the concrete element is lifted out of the mould, forces between the concrete and the formwork surface, due to adhesion and form friction must be added to the self weight. As long as the formwork is fixed to the floor or heavy enough to stay in place (it normally is), dynamic actions must not be considered together with adhesion and form friction. Only in cases where the form is not fixed and not heavy enough to stay in place, inertia forces have to be taken into account on the mass of the element and on the mass of the formwork as well. Later, when the element is moved in the precast plant or on site, self weight and inertia forces both have to be considered.
After the estimation of the forces acting on the element, forces on each anchor have to be calculated, taking into account the position of anchors, number and length of ropes or chains and the static system. In most cases, the aim is to have a statically determinate system, because then the forces on each anchor and on each rope or chain can be clearly calculated. In statically indeterminate systems, load distribution depends on length and stiffness of the ropes, which are mostly unknown. If statically indeterminate systems are used for special reasons, only the statically determinate part should be used in calculating the load distribution, and additional ropes or chains should only be used for stabilization.

Thursday, 10 July 2014

Design Basis for (FRP) Fiberglass Reinforcement Concrete


A design basis for FRP reinforced concrete has been recommended by a number of standards and professional organization. The LRFD basis is recommended by the ACI 440,1R-03; at this time resistance factors are not probabilistically based. ;load factors are those recommended for all concrete structures by AC! 318-95 (1995)
For the design of flexural members reinforced with FRP rebars the ACI 440.1R-03 recommends the following resistance factors:
Flexural capacity (tensile reinforcement only):
ø= 0.5 for an under reinforced beam section (pf< pfb)
ø=0.7 for a substantially over reinforced beam section (pf> 1.4Pfb)
ø= 0.5pf/pfb, for a lightly over reinforced beam section (pfb< p < 1.4pfb)
Shear capacity (stirrups):
ø =0.85 per ACI 318-95.
where Pf is the FRP reinforcement ratio and Pfb is the balanced FRP reinforcement ratio.
Characteristic strength (also called the guaranteed strength) and strain to failure of FRP rebar’s are defined as the mean minus three standard deviations of a minimum of 25 test samples. The design strength, fro, and design failure strain, Efu, are obtained from the characteristic strength and failure strain by multiplying them by an environmental decline factor, CE, which relies on the fiber type in the bar and the type of intended service of the structure. For example, for weather exposed concrete with glass FRP rebar’s, CE is 0.7 (ACI 440.1R-03 2003).
Since FRP rebar’s typically have a lower modulus than steel rebar’s, the serviceability limit state (deflections and crack widths) can often control the design of FRP reinforced concrete sections. The ACI 440.1 R-03 provides procedures for calculating deflections and crack widths in FRP reinforced members.

Friday, 20 June 2014

Do You Know TUF-BAR™ rebar is an environmentally friendly product.........!

Tuf Bar

Tuf Bar Solution
(Fiberglass Rebar)
The 20 years of time period, Tuf-Bar has been in the industry of crafting and advertising high-quality truck and SUV accessories. The values of Tuf-Bar is to build and offer truck and SUV accessories that have excellence built in at an reasonable price. Thus, Tuf-Bar allows you to furnish your ride with superior protection and technique without putting a hollow in your wallet. You can faith Tuf-Bar to convey on their promise every time.

Keeping excellence and worth in mind, every Tuf-Bar creation is crafted with high-class materials and progressive design. So, Tuf-Bar, step bars and Tuf-Bar bull bars are tough enough to survive day by day abuse, delivering the crucial protection for your journey. Actually, Tuf-Bar supports their stainless steel goods with an unbelievable Lifetime Warranty, and their black powder covered products come up with 3-years warranty.
In addition, most parts of the Tuf-Bar and accessories feature are very easy, no-drill fixing that you can complete yourself in just an    hour.

When you are seeing for the best possible choice of Tuf-Bar parts at the lowly prices available, look no further than BP-Composites. We are dealing with a extensive collection of Tuf-Bar products, and we also give you a surety of the lowest prices. Plus, we can ship your Tuf-Bar get right to your front door with no cost

Wednesday, 11 December 2013

Rebar: Steel Reinforcement for Concrete Structures

Rebar is a contraction for the primary fixing in fortified solid: steel bars that are implanted in poured solid footings, dividers, chunks and different structures to make them stronger. Little edges in every bit of rebar make a mechanical association between cement and steel after the cement solidifies. Thus, the completed the process of balance, divider or section picks up respectable quality, particularly in pressure. A fortified solid section or divider can withstand compel connected by extensive soil, by settling, and even (in a few cases) by seismic movement.
Rebar comes in distinctive thickness's, and is now and then covered with a completion to secure against consumption. Construction regulations and designing determinations verify rebar size, dispersing and other steel fortification parts for poured solid structures. To keep the steel persistent, unique lengths of rebar are regularly curved to reach out around corners and covered so they could be entwined with steel tie wire. On bigger structures like cement segments and review shafts, rebar "enclosures" are welded together and positioned inside structures. Cement chunks frequently hold rebar and also welded wire network.
Rebar issues are frequently a component when cement comes up short by splitting, moving or settling. Foremen now and again utilize next to zero steel fortification notwithstanding what building plans call for, essentially to spare on development overheads. An alternate issue can happen when rebar isn't positioned accurately, or in the event that it moves out of position throughout the pour. In the event that the steel fortification is so close it is not possible the surface or edge of the cement, its reinforcing lands are bargained and its less averse to rust, which will debilitate the cement further. There's a high cost to pay if steel support items are crudely fixed preceding pouring a solid structure, and these poor development practices keep establishment repair pros occupied. Luckily, a talented establishment repair pro can depend on different sorts of steel fortification -like steel wharfs, sections and tiebacks, for instance to amend establishment issues that come about because of deficiently strengthened solid.
Contact BP Composites today for structural repair in Edmonton, and to discover increasingly about Rebar.