Composite Reinforcement

The traditional building bars made of steel have been used for reinforcing the concrete structures for already many years. However, regardless their popularity, they have inherent weaknesses. All these weaknesses are determined by those of the material, of which the building bars are made. The greatest weakness of any building bars made of steel consists in their susceptibility to ordinary and chemical corrosion. There are also other disadvantages, the main of which are large weight, electric conductivity and high  heat conductivity.

The polymer reinforcement referred also to as the composite one is free of all the above listed weaknesses. The composite reinforcement has been commonly spread abroad, particularly, in Japan, where it is used for reinforcing the concrete structures, for earthquake stability of which the increased requirements are specified. As regards its composition, the polymer composite reinforcement is divided into the fiberglass one and basalt one. As regards its construction it is of bar type and can be manufactured with either structural or plain profile. Our production facilities are specialized in manufacturing the fiberglass composite reinforcement bars (abbreviated designation: AKP-S). The basalt-plastic reinforcement bars are even more stronger than the fiberglass ones, but they are also much more expensive.

 

Sphere of application

The fiberglass polymer composite reinforcement bars (abbreviated designation: TFB AKP-S) manufactured by our enterprise Thermo Foam Blocks Factory SPC in the Bahrain City according to Technical Specifications TU 2296-001-21541705-2012 are intended for using in the civil engineering:

·         Foundations below the ground level of bedding (up to date, the fiberglass reinforcement bars are the better reinforcing material for making strip foundations and casting the foundation slabs);

·         Light posts, power transmission poles, insulating traverses of the power transmission lines;

·         Road construction: Reinforcing the roadbed, bridges and fences;

·         Reinforcing such objects as: road and pedestrian tiles, fence tiles, curb stones, poles and supports, railway sleepers;

·         structures operated under the conditions of accelerated corrosion of the steel reinforcement and concrete (moorages, dry docks, reinforcing the foreland by concrete casting; in the constructions subject to general corrosion and dynamic loads when being operated.

 

Saving the money due to using the TFB

 

 

While deciding between the application of metal reinforcement and the TFB AKP-S fiberglass one, many persons calculate incorrectly the economic expediency. Many often confine themselves to comparing the price for 1 running meter of steel reinforcement bars with that for 1 running meter of composite ones. But such comparison is fundamentally wrong! What about transportation? What about handling? And so on… The real saving from application of composite reinforcement will be much more that just a difference in the price per running meter. Let us consider, what would be the components of saving your money, should the TFB AKP-S composite reinforcement be used instead of the metallic one:

 

Let us take, for example, the casting of the foundation slab for constructing the house with the area of 100 м2. To simplify the problem, let us assume the slab to be square-shaped with the dimensions of 10х10 meters. The followings can be chosen for reinforcing the slab:

• А-400С steel reinforcement bars with the diameter of 12 mm and spacing of 200 mm in both directions in the top and bottom zones;

• TFB AKP-S 8 fiberglass reinforcement bars with the diameter of 8 mm and spacing of 200 mm in both directions in the top and bottom zones;

(We remind that the tensile strength of the composite reinforcement bars is 2.5 times as much as that of the steel ones with the same diameter. For this reason, the notion of “equal-strength substitution” has been introduced. It means that the composite reinforcement bars may be substituted for the steel ones with the larger diameter, but the same tensile strength).

As follows from a simple calculation, we need 200 reinforcement bars (regardless its type) each having the length 10 running metres, i.e. we need 2,000 running metres (2 km) of reinforcement bars for casting this foundation.

Below we shall list all the aspects constituting the economical advantage in favour of the TFB AKP-S non-metallic reinforcement.

 

 

Saving in the cost of the reinforcement itself

 

• The price for the TFB AKP-S fiberglass reinforcement bars with the diameter of 8 mm is $0.475 /running meter. Respectively, 2 km of this reinforcement will cost 949.9;

• The price for the А-400С steel reinforcement bars with the diameter of 12 mm (in rods being 11.7 m long) is $0.742 /running meter. Respectively, 2 km of this reinforcement will cost $1,485.76 .

The real prices were taken as of the moment of compilation of the article on January 1, 2013. At the moment, the saving in the cost of the reinforcement itself is 1,485.76 – 949.9 = $535.86 . But there is more to come!

 

 

Saving in loading and transportation

 

• The weight on 1 meter of the TFB AKP-S 8 fiberglass reinforcement bars with the diameter of 8 mm is 0.075 kg. Respectively, the total weight of 2,000 meters of composite reinforcement will be 0.075 kg/running meter * 2,000 running meters = 150 kg. The TFB AKP-S fiberglass reinforcement bars with the diameter of up to 10 mm can be bought in coils each containing 100 running meters. The outer diameter of such a coil exceeds slightly 1 metres. Such reinforcement has no residual strain coefficient, once the coil will be untied, the reinforcement bars will become straight by themselves as a spring. Therefore, 2,000 running meters of the TFB AKP-S 8 reinforcement bars with the diameter of 8 mm are 20 coils each containing 100 meters. The weight of one coil containing 100 meters of reinforcement is 7.5 kg. The total weight of 20 coils is 150 kg. The whole reinforcement can be transported in a jeep, car boot, mini bus or light lorry of Hazel type;

• The weight of 1 meter of the А-400С metallic reinforcement bars with the diameter of 12 mm is 0,89 kg. Respectively, the total weight of 2,000 meters of steel reinforcement will be 0.89 kg/running meter * 2,000 running meters = 1,780 kg.   The reinforcement bars with the diameter of 12 mm are not sold in coils. It is most likely that you will buy the reinforcement in bars with the length of 12 m (or, more exactly, 11.7 meters). To carry such reinforcement you will need a long vehicle, such as a semi-trailer truck with the body of respective length. It is theoretically possible to take the bars with the length of 6 m, but it will be necessary to pay for cutting 12 m of bars and carry them by a truck with the body having the length of 6 m (that will be allowed by the carrying capacity and body length), but it will be necessary to tangle these bars once again when splicing and cut off the excesses that will be quite wastefully and add laboriousness to the tying process.

As a result, we have obtained:

The steel reinforcement is 11.87 as heavier as the composite one! To carry the same, it will be necessary to order the large vehicle that will cost at least $213.012. It should be noted additionally that it can be impossible for a large vehicle such as a semi-trailer truck to reach directly the construction site. Should the matter be a gardening establishment or settlement with narrow streets, it will be most like that the enforcement bars will have to be carried in human arms from the place which could be reached by the truck.

The TFB AKP-S composite enforcement can be carries in a private car without hiring the carrier's vehicle!

 

SAVING IN HANDLING (weight)

• The TFB AKP-S8 fiberglass reinforcement consists of 20 coils each containing 100 running metres and having the weight of 7.5 kg (as shown in the preceding item, the weight of 2,000 meters of such reinforcement is as little as 150 kg). It can be carried in a private car. You can load and unload such cargo by yourselves, with employing neither loaders, nor special machinery; it will take you about 10 minutes;

• А-400С metallic reinforcement bars with the diameter of 12 mm. We have already determined in the preceding item that weight of 2,000 meters of such reinforcement is 1,780 kg. You will be hardly able to handle such quantity of reinforcement bars by yourselves and for short period of time. It is most likely that you will have to bear additional expenses for loading/unloading the steel reinforcement. By the way, should the long vehicle, such as a semi-trailer truck be unable to reach directly to the boundary of your construction site due to narrowness of the streets, your loaders will have to make long and tiresome walks with steel reinforcement bars on their shoulders from the place of stop of the truck to the site. The latter can cause an additional amount of money to be paid to the loaders.

 

Saving in cuttings

• Having bought the TFB AKP-S8 fibreglass reinforcement bars with the diameter of 8 mm in coils each containing 100 running metres, you can cut them in pieces each having the length of 10 running metres and manage without waste (in the example, we consider the foundation slab with the dimensions of 10х10 metres);

• А-400С metallic reinforcement bars with the diameter of 12 mm. It is most likely that you will have to buy this reinforcement in bars with the length of 11.7 running metres. Each bar has to be shortened to 10 running metres by cutting off 1.7 running metres from each bar. The total number of bars in our slab will be 200, therefore, the quantity of waste will be 340 running metres. To be more correct, they are not waste, but shortage. In other words, while buying the steel reinforcement you will have to buy 200 bars each having the length of 11.7 metres instead of the same quantity of bars being 10 metres long. Converting into the final figure gives us 2,340 running metres of steel reinforcement instead of 2,000 running metres. Should these excessive 340 metres of steel reinforcement be converted into money, we will obtain 340 running metres * 0.742 USD/running metre = 252.58 US.

Saving in electricity and consumables

• TFB AKP-S d8 fibreglass reinforcement bars. Do you know that such reinforcement bars can be cut by means of good wire cutters? Firstly, in this case you will not have to buy a lot of disks for an angle grinder and, secondly, to cut such reinforcing bars you will need no electric power at all;

• А-400С metallic reinforcement bars with the diameter of 12 mm. For cutting the steel reinforcement bars (minimum 200 cuts), you have to buy a lot of disks for an angle grinder, moreover, the construction site shall be provided with electric power as early as at the stage of preparation for casting the foundation.

LET'S SUMMARIZE

Having summarized the aforesaid, we can say with certainty that choosing the composite fibreglass reinforcement for the foundation does not only consist in the difference in the cost of the reinforcement itself being equal to 535.85 USD, but is to be calculated from the formula:

difference in the cost of the reinforcement bars themselves + cost of transportation by a long vehicle + cost of loading/unloading + overpayment for cuttings + cost of the disks for the angle grinder.

The total amount of the saving will exceed (for this example): 1,011.80 USD.

Remember that, in addition to saving the money, you will also acquire the corrosion-resistant, non-magnetic and non-screening reinforcement having low heat conductivity (it will not become a “heat bridge”).

 

Advantages of the TFB AKP reinforcement

• The strength is 2-2.5 times as much as that of the traditional metallic bars with the same diameter. It would make it possible to either increase the cell dimensions when tying the grid (in case of using the TFB AKP-S reinforcement bars with the diameter equal to that of the steel reinforcement bars) or to retain the same cell dimensions, but use the TFB AKP-S reinforcement with lesser, but “equal-strength”* diameter. In both cases, the considerable reduction of the weight of the ready construction will become an additional advantage.

• Chemical and corrosion resistance. High resistance to water, alkaline and acidic media. It is related to the products of the 1st group as to resistance to chemical attack. It guarantees the durability and impossibility of cracking and destruction of reinforced-concrete structures due to internal stresses occurring in the process of corrosion and corrosion swelling as it takes place in cases of using the steel reinforcement.

• Low heat conductivity in comparison with metal. The heat conductivity of the composite materials based on fibreglass and basalt plastic is more than 10 times less than that of metal. Therefore, the composite building bars are not a cold bridge in the reinforced-concrete structure, unlike the steel ones.

• The thermal expansion coefficient is the same as that of concrete that excludes the breaks of the reinforcement and cracking in the concrete layer under the action of the temperature differences.

• Such reinforcement is dielectric (does not conduct the electric current), magnet- and radio-transparent.

• Lower density and, as a consequence, the weight is 3.5-4 times less than that of the traditional steel one having the same diameter and 10 times lighter in case of using the “equal-strength” diameter.

• Such reinforcement is less expensive than the steel one due to the possibility of using the smaller diameter with the same strength (“equal-strength” diameter). Please, give oneself the trouble to see the full description of the components of your saving of monetary means, time, number of man-hour, electric power, consumables, etc. in the article “SAVING THE MONEY DUE TO USE OF THE COMPOSITE REINFORCEMENT”.

 

Saving in weight and volume

When choosing particular goods, the buyer only compares usually the prices for the goods themselves while believing that the saving in transportation cannot be considerable. To illustrate that it is wrong, we'll make a simple calculation.

Let you need 40,000 running metres of А-3 (А400) steel reinforcement bars with the diameter of 12 mm for casting the foundation slab. The calculations are tabulated:

Reinforcement mark

Material

Strength

Volume, cubic metres

Weight, kg

Price, roubles

А-3 (А400)
D =12 mm, L=40 km.

steel

initially required

18.09

38,160

29,715.32 USD. (based on 837.26 USD/ton or 0.74 USD/running metre)

TFB AKP-S
D=8 mm, L=40 km.

composite

equal to the required one

8.04

3,000

18,998.32 USD. (based on 0.475 USD/running metre)

Compare the first row of the table with the last one. Using the composite reinforcement bars instead of steel ones with the equal-strength diameter will reduce the volume 2.25 times and the weight 12.72 times! The cargo specified in the first row of the table could not be transported by a single truck (the limitation as to the maximum weight of the cargo is 20 tons), while that specified in the last row of the table could be transported even as small truck as Valday (in case of transportation in the form of bundles/coils or in case of transportation in the form of rods with the length of 6 metres folded as a horseshoe). Do you see now, how considerable could be saving in transportation? Please note that the weight of the reinforced-concrete structure will be also reduced by 35,160 kg.

Add the possibility of ordering the reinforcement in the form of coiled bars of any length convenient for you. For example, should you will cast the slab with “cards” being 48 metres long, we could provide you with the reinforcement in the form of coiled bars with the lengths of 48 or 96 metres. In this case you will get saving due to absence of jointing laps and waste. Besides, you will speed up the process of tying the reinforcement cage due to excluding the works for jointing short bars into a single long one.

The saving in the cost of the reinforcement came to 10,717 USD. (Saving: 56,4%).

The saving in weight came to 12.72 times that means 3,000 kg instead of 38,160 kg.

The saving in volume is 2.25 times or 8.04 m3 instead of 18.09 m3.

 

Table of equal-strength substitution

The equal-strength diameter is considered as such outer diameter of the polymer composite reinforcement bars, with which its strength corresponds to that of steel reinforcement bars of the specified diameter.

Diameter,
mm

Weight per running metre in kg

Number of metres per tonne

Diameter,
mm

Weight per running metre in kg

Number of metres per tonne

Steel reinforcement bars, class А-III (А400С)

Composite reinforcement bars

6

0.22

4,505

4

0.02

50,000

8

0.4

2,532

4

0.02

50,000

10

0.62

1,621

6

0.047

21,276

12

0.89

1,126

8

0.075

13,333

14

1.21

826

10

0.126

7,936

16

1.58

633

12

0.169

5,917

18

2

500

14

0.246

4,065

20

2.47

405

16

0.44

2,272

22

2.98

336

18

0.58

1,724

25

3.85

260

20

0.73

1,370

 

 

Substitution of the reinforcement bars according to their physical and mechanical properties

 8 АIII

 6 ASP (АСП)

10 АIII

7 ASP

12 АIII

8 ASP

14 АIII

10 ASP

16 АIII

12 ASP

18 АIII

14 ASP

20 АIII

16 ASP

 

DIAMETER

LENGTH PER TONNE OF METAL (IN RUNNING METRES) (AIII)

Weight per metre of reinforcement bars, metal A III

Reinforcement bar diameter, mm, ASP fibreglass

Weight per metre of reinforcement bars, ASP fibreglass, kg

8 АIII

2531.65

0.395

6(ASP)

0.05

10 АIII

1620.75

0.617

7(ASP)

0.07

12 АIII

1126.13

0.888

8(ASP)

0.08

14 АIII

826.45

1.21

10(ASP)

0.12

16 АIII

632.91

1.58

12(ASP)

0.2

18 АIII

500

2

14(ASP)

0.26

20 АIII

404.86

2.47

16(ASP)

0.35

 

Comparative characteristics of metallic reinforcement bars of class AIII and the ASP fibreglass reinforcement bars

Characteristics

Reinforcement bars

А-Ш (А400С)

Composite

Material

Steel

Glass roving bound by the polymer based on the epoxy resin

Tensile strength, MPa

390

1,300

Modulus of elasticity, MPa

200,000

55,000

Relative elongation, %

25

2.2

Thermal conductivity coefficient, W/(mּ0С)

46

0.35

Lineal expansion coefficient, αх10-5/°С

13-15

9-12

Density, t/m³

7.8

1.9

Corrosion resistance to aggressive media

Corrosion susceptible

Corrosion resistant material

Heat conductivity

Heat conductive

Not heat conductive

Electric conductivity

Electricity-conductive

Dielectric (not electricity conductive)

Profiles manufactured

6-80

4-20

Length

Rods 6-12 m long

In accordance with the buyer's application

Ecological compatibility

Ecologically compatible

Non-toxic, related to the 4th class as to the degree of impact on the human organism and environment (low-hazard).

Durability

In accordance with the construction norms

The expected durability is at least 80 years

Substitution of the reinforcement bars according to their physical and mechanical properties

6 АIII

8 АIII

10 AIII

12 АIII

14 АIII

16 АIII

18 АIII

20 АIII

4 ASP

6 ASP

7 ASP

8 ASP

10 ASP

12 ASP

14 ASP

16 ASP

Weight, kg (in case of equal-strength substitution)

6 А-III - 0.222

8 А-III – 0.395

10 A-III – 0.617

12 А-III – 0.888

14 А-III – 1.21

16 А-III – 1.58

18 А-III – 2.0

20 А-III – 2.47

4 ASP – 0.02

6 ASP – 0.05

7 ASP– 0.07

8 ASP – 0.08

10 ASP – 0.12

12 ASP – 0.20

14 ASP – 0.26

16 ASP – 0.35

 

 

When designing the building structure using the composite reinforcement, the equality of the loads to be applied to the reinforcing members should be followed. The rules of substitution are given in the following table:

Metallic reinforcement bars of class III (А400С) to GOST 5781-82

ASP Composite reinforcement bars 

6 АIII

Fsec = 28.3 mm2

Рcalc = 10,045 N

5 ASP

Fsec = 12.56 mm2

Рcalc = 15,072 N

8 АIII

Fsec = 50.3 mm2

Рcalc= 17,857 N

6 ASP

Fsec = 19.63 mm2

Рcalc= 23,550 N

10 АIII

Fsec = 78.5 mm2

Рcalc= 28,653 N

7 ASP

Fsec = 28.26 mm2

Рcalc= 33,912 N

12 АIII

Fsec = 113.1 mm2

Рcalc= 41,282 N

8 ASP

Fsec = 38.5 mm2

Рcalc=  46,158 N

14 АIII

Fsec = 154 mm2

Рcalc= 56,174 N

10 ASP

Fsec = 63.6 mm2

Рcalc= 76,302 N

16 АIII

Fsec = 201 mm2

Рcalc= 73,402 N

12 ASP

Fsec =  95  mm2

Рcalc= 113,982 N

18 АIII

Fsec = 254 mm2

Рcalc= 92,893 N

12 ASP

Fsec = 95 mm2

Рcalc= 113,982 N

20 АIII

Fsec = 314 mm2

Рcalc= 114,683 N

14 ASP

Fsec =  132.7 mm2

Рcalc= 159,198 N

22 АIII

Fsec = 380 mm2

Рcalc= 138,737 N

14 ASP

Fsec = 132.7 mm2

Рcalc= 159,198 N