LRB (Lead rubber bearing)

Spherical bearing
2019年1月10日
High Damping Rubber Bearing(HDR Bearing)
2019年3月2日

LRB (Lead rubber bearing)

Lead rubber bearing (LRB) are rubber bearings, consist of alternate layers of elastomeric material and vulcanized reinforcement steel plates with a cylindrical central lead core. The energy dissipation allowable to achieved an equivalent viscous damping coefficient up to about 30%, due to high absorption capacity of the lead core.

As the reinforcement steel plates are fully embedded in the elastomeric material, they are sealed, and therefore protected against corrosion. The devices are manufactured with rubber vulcanized to the top and bottom connection plates. The bearing can be also be supplied with additional anchor plates, allowing easier replacement of the device in case of maintenance needs.

Design principle

The working principle of BAOLI lead rubber bearings is the isolation of the base and the transfer of energy from the ground to the structure during an earthquake.

Rubber and steel laminate supports are designed to support the weight of the structure and provide flexibility after yielding. After the earthquake, the rubber provides isolation and re-centring of the bearings. Under shear deformation, the lead core is plastically deformed,  while dissipating energy through heat.

Applicable standards

  • European Standard: EN 15129;
  • American Standard: AASHTO;
  • Other standards, according to customized requirement.

Material

elastomer

The elastomeric used in the manufacturing of lead rubber bearing should be specified in the project documentation as either natural rubber (NR) or chloroprene rubber (CR) as the raw polymer.

Physical and mechanical propertied of elastomer

Characteristics Requirements Test Methods
G Modulus  (MPa) 0.7 0.9a 1.15 ISO Equivalent national  standard
Tensile Strength (MPa)

Molded Test Piece

Test Piece from Bearing

Minimum elongation at break(%)

Molded Test Piece

Test Piece from Bearing

 

≥16

≥14

 

450

400

 

≥16

≥14

 

425

375

 

≥16

≥14

 

300

250

ISO 37

type2

GB/T

528-1998(Type 2)

Minimum Tear Resistance(KN/m)

CR

NR

 

≥7

≥5

 

≥10

≥8

 

≥12

≥10

ISO 34-1

Trouser

(Method A)

GB/T 529-1999

(Pants type)

Compression Set(%)

24h; 72℃

 

CR ≤15

NR≤30

ISO 815

φ29×12.5mm,

Spacer: 9.38mm,-25%

GB/T

7759-1996

Accelerated Ageing

(Maximum change from unaged value)

-Hardness(IRHD)

NR  7 d , 70℃

CR  3 d, 100℃

-Tensile strength(%)

NR  7 d , 70℃

CR  3 d, 100℃

-Elongation at break(%)

NR  7d , 70℃

CR  3d, 100℃

 

 

 

 

-5+10

±5

 

±15

±15

 

 

±25

±25

ISO 48

ISO 188

GB/T

6031-1998

GB/T

3512-2001

Ozone Resistance

Elongation: 30% – 96h

40℃±2℃

NR 25pphm

CR 100pphm

No cracks ISO 1431-1 GB/T 7762-2003

 

Steel plates

Reinforcing plates, the top and bottom plates are made from rolled carbon steel conforming to EN10025, EN10083, and EN10088/SHTOA36 or A570.

Lead core

Lead with a minimum purity of 99.9%, which ensured the LRB have a good quality.

Lead rubber bearing with one lead core


QUALITY CONTROL

-BAOLI elastomeric bearings were manufactured according to EN15129, they have been tried and tested under demanding traffic conditions and have a long life-span. They have been used successfully around the world for more than 25 years.

-External quality complies with the regulations of the European standard EN15129 and is a further guarantee of the consistent quality of  BAOLI products.

-Professional inspector and a full set of testing equipments including shear tester, ozone resistance tester, aging tester, etc. All of these guarantee a consistent quality level for all the BAOLI elastomeric bearings.

QUALITY CONTROL

-BAOLI elastomeric bearings were manufactured according to EN15129, they have been tried and tested under demanding traffic conditions and have a long life-span. They have been used successfully around the world for more than 25 years.

-External quality complies with the regulations of the European standard EN15129 and is a further guarantee of the consistent quality of  BAOLI products.

-Professional inspector and a full set of testing equipments including shear tester, ozone resistance tester, aging tester, etc. All of these guarantee a consistent quality level for all the BAOLI elastomeric bearings.

15000kN compression shear tester

Compression test for elastomeric bearing

Ozone aging & hot air aging tester

Rubber tensile strength tester

Rubber tensile strength tester

Application

BAOLI LRB used in bridges, highways, building and other constructions.

Advantage

  • Quality assurance: Quality control from raw material to finished product.
  • On time delivery “No waiting around”.
  • Cost saving options “Getting you the best price”.
  • Small quantity acceptable “Every piece is valuable to us”.
  • Professional packing plan to save cost for customers, customers won’t suffer any problem.

wooden case with PE films and pearl cotton(as per customer’s need)

QUOTES

The follow detailed are necessary to provide you with a quote:

If the size has already been ascertained:

-Max. bearing dimension : length, wide, thickness

-Material quality: CR/ NR

Otherwise, please provide us with the follow information, so that we can calculate and provide your desired lead rubber bearing:

-Vertical load: (maximum and minimum)

-Displacement

-Bearing rotation

-Bearing shape: (round or rectangular)

-Contact surface(steel or concrect)

-Maximum dimensions(when space for bearing is limited)

Quotes are processed immediately and delivered promptly.

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