Hydraulic Stressing Jack, Factory China

Hydraulic stressing jacks are used in various applications within the construction and engineering industries, primarily for prestressing concrete structures.

With competitive price and timely delivery, YUANXIAN sincerely hope to be your supplier and partner.

' Bridges: Hydraulic stressing jacks are frequently employed in the construction of prestressed concrete bridges. They are used to tension the steel tendons that run through the bridge beams or segments, thereby imparting compressive forces to the concrete.

' Buildings: In high-rise buildings and other large structures, hydraulic stressing jacks are used to prestress concrete floor slabs, beams, and columns. This enhances the load-carrying capacity and reduces the risk of cracking under heavy loads.

' Parking Structures: Prestressed concrete is often used in parking garages and structures where large spans and heavy loads are common. Hydraulic stressing jacks are used to apply the necessary force to prestress the concrete elements, ensuring structural integrity and longevity.

' Railway Sleepers: Prestressed concrete sleepers (railroad ties) used in railway tracks benefit from prestressing to withstand the dynamic loads of passing trains. Hydraulic stressing jacks are employed to tension the tendons within the sleepers during manufacturing.

' Repair and Retrofitting: In existing structures, hydraulic stressing jacks can be used for repair and retrofitting purposes. They can help restore or enhance the structural capacity of aging or damaged concrete elements by applying additional prestressing force.

' Pre-stressed Concrete Pipes: Hydraulic stressing jacks are used in the production of prestressed concrete pipes, which are commonly used in drainage systems, culverts, and sewage pipelines. Tensioning the steel wires or strands inside the pipes helps improve their strength and durability.

The YCW C series jacks for stressing multi strands are the fourth generation lightweight jacks successfully launched by our company after further improving and optimizing the structure and size based on the third generation jacks. It has a small size, light weight, good sealing performance, high strength and reliability, and strong universality, making it a replacement product for the third generation of jacks.

Widely used in post tensioning prestressed construction, with different components, it can tension clamp type group anchors, DM type pier head anchors, and LZM type cold cast anchors of different systems. Widely used in pre tensioned and post tensioned prestressed concrete structures, components, bridges, power stations, highways, high-rise buildings, geotechnical anchoring, dam foundation anchoring and other construction projects.

ItemNominaltensioning force (KN)Nominal oil pressure (KG)TensilePiston Area(m2)Area of drawback piston (m2)Return oil pressure (mpa)Diameter of center hole (mm)Tensioning stroke (mm)Weight of main unit (kg)Overalldimension of main unit (mm)Dimension of fixing nut seam allowance (mm)Dimension of piston seam allowance (mm)ModelYCW60B.15×10-20.41×10-2'25ΦΦ170×340Φ102Φ90YCW80A.508×10-20.471×10-2'25ΦΦ200×343Φ102Φ102YCW100C.91×10-20.78×10-2'25ΦΦ216×349Φ149Φ130YCW150C.02×10-21.61×10-2'25ΦΦ280×366Φ170Φ156YCW200C.77×10-21.84×10-2'25ΦΦ310×310Φ196Φ176YCW250C.59×10-22.80×10-2'25ΦΦ350×369Φ210Φ186YCW300C.77×10-23.13×10-2'25ΦΦ385×370Φ252Φ216YCW350C.480×10-23.46×10-2'25ΦΦ415×390Φ252Φ252YCW400C.610×10-24.60×10-2'25ΦΦ440×390Φ252Φ252YCW500C.05×10-24.77×10-2'25ΦΦ490×423Φ302Φ302YCW600C.10×10-26.83×10-2'25ΦΦ530×443Φ362Φ302YCW650C.33×10-26.29×10-2'25ΦΦ575×465Φ362Φ362

Single mono strand  jack

According to the different requirements for the diameter, tension value, and equipment weight of prestressed steel strand, there are three main specifications of jacks for tensioning a single prestressed steel strand: YDC260QX type, YDC360Q type, and YDCSOOQ type, all of which are through center front clamp jacks. Among them:

1. The YDC260QX jack is mainly used for pre tensioning and tensioning of M15 and M13 anchoring series prestressed tendons;

2. The YDC360Q jack is mainly used for pre tensioning and tensioning of M18 anchoring series prestressed steel tendons;

3. The YDC500Q jack is mainly used for pre tensioning and tensioning of M22 anchoring series prestressed steel tendons;

ItemNominaltensioning force (KN)Nominal        oil pressur  e (KG)TensilePiston  Area(m2)Area         of drawback     piston (m2)Diameterof center hole         (mm)Tensioning stroke        (mm)Overalldimension of main       unit (mm)Weight of         main    unit      (kg)The strand diameter could be pressed,mmReserved length of steel strand ,mmOil PumpModelYDC260QX.771×10-31.335×10-3ΦΦ115X.24,12.ZB4-500YDC360Q.696×10-32.298×10-3ΦΦ130X.ZB4-500YDC500Q.950×10-31.960×10-3ΦΦ155X.ZB4-500

In July , we started to deliver a series of customized Stressing Jack to some precast concrete operators. This 100 metric ton Stressing Jack works on a 200mm length stroke and it is able to perform simultaneous stressing job on 4 PC strand spaced 50mm apart.

TMG successfully helped the operators to reduce up to 75% of their mapower cost and also increased the production cycle time. And this is a tremendous improvement on the overall work productivity and efficiency.

As TMG is specialized in all sorts of customization work, we are constantly working on more innovative and groundbreaking products. This will inevitably bring values and reduction in operation cost for our users, both on prestressing and post tensioning jobs.

The development of technology brought us many conveniences and also altered our tradional ways of running businesses. And TMG believes that by embracing and implementing appropriate adaptation with technology, we can remain relevant and also ahead of the changes in the prestressed concrete industry.

Bearing Plate is a very important element in a post tensioning system.  It serve the purpose of transfering prestressing force derived from the tendon (tensile element, eg. PC strand) to the concrete. And it is precisely in this, that explains what we want to achieve in prestressed concrete structures, and thus we take a special interest on the Bearing Plate.

In our earlier blog post we shared on the testing we conducted on 'Load Transfer and Static Load Test of Anchors in accordance to European Technical Approval (ETAG 013)', we posted some photographs of Bearing Plate casted into concrete blocks for Load Transfer Test. Well, this is to test the ultimate load bearing capability of the Bearing Plate (by means of a Stressing Jack) under a real-life situation. As ETAG 013 specification clearly states under Load Transfer to the Structure; 'Post Tensioning systems shall be able to transfer a specified percentage of the tensile element ultimate strength from the anchorage into the concrete structure, of a defined strength class of concrete, without undue cracking of the structure, and at deformations which stabilise within a given time frame'.

However, we are not going in-depth on this test procedure and result. Rather we are taking an interest on the manufacturing of the Bearing Plate. Bearing Plate is generally manufactured with ductile iron (eg, ASTM A536, Grade 80-55-06) or grey iron (eg, HT200, GB/T-), casted in a steel foundry. There are numerous ways in the production of Bearing Plate. From an automatic production line (eg, DISA) to a brick & mottar method of using moulds, very much like how we produce precast concrete products.

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We take a particular interest in a method we are familiar with, and that is, the usage of polyfoam to bring our Bearing Plate to life!

The polyfoam is produced to the exact same shape and size as the actual Bearing Plate. And then a layer of clay is coated over the polyfoam to form an 'temporary' mould over it. Molten iron is then poured into this temporary mould through a small opening, and the polyfoam inside will then be burnt away. With the disappearance of the polyfoam, the molten iron will then filled up the temporary mould. Once the molten iron cools down and harden, the removal of the exterior clay will then give us the Bearing Plate we wanted.

We posted some photographs of our Bearing Plate production process and we hope this will provide some insights of our daily production activities.

Duct is an important element for bonded post tensioning work. It is essential as it creates a void for the tendon or tensile element. By and large, steel corrugated duct provides the most economical solution to bonded post tensioning work.

Steel corrugated duct are manufactured from a long galvanized strip of steel, normally in the range of 0.25 ' 0.40mm in thickness and can be 30 ' 80mm in width. It depends on the type of duct forming machine used. These strips are then pressed into a corrugated form before they are fed into a turning wheel to make the edges interlock, and forming into a pipe. And in post tensioning terms, we call this pipe a 'duct'. And duct can come in 2 types of shapes, round and flat. A steel corrugated flat duct is pressed into shape from a steel corrugated round duct and it is generally used for slab anchorage (not limited).

Duct plays a critical role in providing a corrosion protection environment to the tensile element or tendon (eg. PC Strand). And steel corrugated duct offers excellent bonding behaviour to tendon grout and also the concrete around it. And it is precisely because the duct is a protection to the tendon, its quality is paramount.

Due to the way the steel corrugated duct is produced, bad quality duct can cause huge problems like 'bleeding' during the construction process. Most of the time, it is the bad interlocking of the edges between adjacent strips that causes the duct to collapse under the weight of the concrete. This results the concrete to leak into the duct (term 'bleeding') and bond with the tendon even before stressing commence.

Operators are well aware of the repercussion bleeding can cause. During stressing, it causes the tendon elongation to fall under the required length even though the stressing jack and pump had worked to its required load. To sum it up, we call this prestressing lost (due to frictional effect). This is a situation everybody wants to avoid.

Duct is also available in plastic form, generally made of polyethylene / polypropylene material. Plastic duct has lesser bleeding issue and it is more commonly found in corrosive environment like waste water treatment tanks, acid tanks, silos etc. However steel corrugated duct is still the preferred choice for providing a homogenous environment to prestressed concrete structure, primarily due to its excellent bonding characteristic. And in some countries, plastic duct are barred because of fire safety regulation. This is because the burning of plastic during a fire hazard can emit poisonous gases and it is harmful to humans. 

TMG visited a few project sites and with the blessing of the main contractors, we managed to film the process of steel corrugated duct production. The source of the duct forming machine remains unknown.

Recently, TMG delivered 8 containers of Anchor Head, Bearing Plate and Wedge for a project in South Asia. This project uses a mixture of slab anchors of 4 and 5 strand, and multistrand anchors of 3 to 19 strand. All supplied anchors are for 15.20mm strand size. As post tensioning is becoming more popular in developing countries, we are seeing an upward trend in prestressed concrete structure design.

Just 20 years ago, prestressing seems to be a taboo in these developing countries. Despite the fact that post tensioning can bring a lot of tangile benefits to the whole structure, developers and contractors are conservative in accepting the advantages that it can bring. Many were septical and conventional in the way they viewed civil construction. The growth and popularity of internet helped and transformed the development of post tensioning. With information now easily available over the internet, developers and consultants are more well informed and have better understanding of post tensioning. This information-age development also accelerated the transformation and acceptance of post tensioning, from an unfamilar technology to a widely accepted one today.

As market demand for post tensioning increases, the surge in post tensioning accessories supplies also effected the cost of carrying out such construction to be more transparent, thus bringing benefits to developers and contractors. Products like PC strand, Stressing Equipment (Stressing Jack, Pump, Grouting Machine etc), post tensioning accessories (Anchor Head, Bearing Plate, Wedge etc) become widely available and can be delivered with short lead-time.

Below are some photographs of TMG Anchor Head (before packaging) in our storage warehouse, ready for shipment.

E-Force Engineering Pte Ltd, our longtime strategic business partner, was presented with Luminary Class Award during Singapore Prestige Class Awards ' Ceremony in Shangri La Hotel on 9th April .

E-Force is a specialist post tensioning company with presents in Singapore, South-East Asia and many parts of Middle East. They specialised in prestressed concrete structural works, primarily for buildings, logistic warehouses, parking facilities, and other special structures. Some of their prominent projects are; the largest mall (Safeer Mall), the biggest Islamic Mosque (Sheikh Zayed Islamic Centre) in Fujairah, as well as the largest resort development (Mina Al Fajer) in Dibba, United Arab Emirates. The prominent Al Hussain Tower in Olaya area, Riyadh, Kingdom of Saudi Arabia, is also one their many achievements.

E-Force's deep understanding of prestressing work and diverse knowledge on structural works made them the preferred choice among the post tensioning specialists in many regions. And equipped with a complete range of Stressing Jack and other accessories, E-Force is ready to undertake any type of post tensioning works with its certified European Technical Approval (ETAG 013) system.

Having worked along with E-Force team of committed members since their establishment, TMG Global Pte Ltd is confident that E-Force will continuously bring benefits and values to the construction industry.

Moving ahead, TMG and E-Force is embarking on another milestone on Bridge Cable construction. We had seen the dramatic increase in Stay Cable demands over the last few years. And the dynamic requirements to these challenges prompted for more creative and ingenious solutions to meet these ever-changing demands. TMG had since developed a Compression Fitting Stay Cable System in view of this trend. Using the same working principle for anchorage with PC Wire, Compression Fitting Stay Cable System uses PC Strand to further increase the working and dynamic load. And this revolutionary innovation elevates further enhance the dynamism in Cable-stayed bridges.

Lastly, we wish E-Force Engineering Pte Ltd every success on their endeavouring path.