civil techniques

EXPANSION JOINTS

abbu riyaz 30 Apr, 2023

The usage of EXPANSION JOINTS discuss and explains in this post. This is the main member in the construction of a bridge. A bridge constructs with many major components like, the pile foundations, pile caps, columns, beams, decks, etc,. The top slab of bridge known as decks. These decks constructs at specific lengths with small gaps at specific intervals between them. These gaps provides for these concrete slab decks to expand and contract. This implements to avoid crack formations and spreading of cracks to other deck slabs. This causes by the temperature change, drying shrinkage, live load etc. These gaps seals with elastic sealants. These sealants are elastic members provides ways for concrete to is expansion and contractions in changing environments.

This expansion joint damages among bridge members causes by the increase of traffic load, improper installation, and careless repairs,etc. It causes a bad ride, accidents leads to traffic. And the frequent repair causes the heavy traffics. This increases the maintenance cost of bridges.

EXPANSION JOINS

The gaps seals with the watertight elastomeric profiles. It allows enough vertical movement to permit bearing replacement, without the need to dismantle the bridge expansion joint.

The method of using copper plates employs. And this method is cost-effective. This provide long-life, compare to other systems.

Its done by replacing an elastic system with the pre-fabricated copper plates. These designs as per requirements for bridge decks. And inserts into expansion joints. And provides a free way to concrete for its expansion and the contraction.

The Advantages

Some of the major advantages explains as follows,

This system stands a change of temperature, contraction, and cliff of concrete.
Provides smooth movement in deck slab roads.
Not necessary to remove the entire expansion joint.
This reduces the time for repairing works.
Reduces the maintenance.
Highly economical.
This system will easily apply on existing bridges according to their types.

civil techniques

FRP Coating

abbu riyaz 30 Apr, 2023

FRP Coating makes onto the surface of various products. And use in the leak-proofing of rooftops, factory floor, chemical industries, anti-corrosion treatment plants, concrete tanks, pipe fittings, and much more. It helps to protect from corrosion, chemicals & salts. It provides excellent performance. And a long-lasting time.

Procedure of FRP

There are several procedures for coating of FRP. And they are,

Check and make appropriate roughness for the surface.
Make sure the surface is dry.
Filling with the plate
Filling with resin.
Providing fiberglass over resin
Finishing top coat.

These procedures for coating of FRP makes with great care. The entire FRP coating process to carry out in a controlled environment. This makes a strong bond between the plate materials with resins and fibers.

1. Fill the plates where the pipes and rooftops need to leak proof.

Filling the plates where the pipes and rooftops of the building to repair are the first steps. In this, the rooftops are carefully cover or seal tight with plates. These plates to be cut to a required size and shape according to repair areas.

2. Filling with Resin

Filling with resin is the second step in the FRP coating process. Fill the top surface of rooftops which needs to protect from corrosion with resins.

3. Laying Fiber Glass

The third step in FRP coating is laying fiberglass. Lay the fiberglass over the resin carefully.

4. Finishing

Finish filling with plates, resin, fiberglass on the surface of rooftops.

Advantages of FRP coating

The advantage of fiberglass is that it easily mold into any shape.

cost-effective
Design Flexibility
Non-conductive
Durable
Corrosion Resistant
Eco-Friendly

HEALTH AND SAFETY

This process cause skin irritation. Wear helmets, safety shoes, Nose Mask, safety glasses, rubber hand gloves. The entire FRP coating process to carry out in a controlled environment. This makes a strong bond between the plate materials with resins and fibers.

civil techniques

Concrete Honeycomb

abbu riyaz 30 Apr, 2023

Concrete honeycomb is becoming a serious issue nowadays. The Concrete make to form various structural elements like Columns, Beams, Foundations, Slabs. Concrete pour in formwork, it starts to flow like water so cavities/voids form when concrete does not reach all places. It appears like honey bee nest. If it does not vibrate properly it leaves voids exposing the aggregate. Honeycomb reduce strength. And provide passage for water that corrodes the reinforcement. The solution here is to ensure that joints are well sealed and leak-free.

1. Cause of Concrete Honeycomb

Insufficient compaction to concrete.
Less cover to reinforcement bars.
Concrete already set before placing.
High concrete free fall while pouring
More coarse aggregates than designed mix proportions and oversized aggregates.
Improper placement of bars at column and beam junction.
Addition of more water than designed at the site for achieving workability.
Steel congestion not allowing concrete flow to all corners.

2. Repairing Concrete Honeycomb

Durability and strength of concrete will improve without making damages to concrete structures using cempatch. It is suitable for wide range of industrial environments such as warehouses, loading bays, bridge deck, car parks and ramps.

3. How to repair concrete honeycomb

Honeycomb seen on concrete structure prepares by wire brush, hammering,etc., to produce a clean, aggregate exposed finish, free from contaminants. Any expose steel to completely uncover. Remove all rust scale or corrosion products. This makes using cempatch mix with cement to a required amount as per the size of honeycomb.

4. Application

Mix Cempatch to ordinary cement mortar as required depending upon the size of honeycomb to repair. Ensure a good compaction of the pre-dampened substrate. Fill and level up to existing profile of the surrounding concrete using a float or trowel. Once Cempatch Repair Concrete has achieved final set use appropriate curing methods to ensure good bonding.

5. HEALTH AND SAFETY

This process may cause skin irritation. Wear required PPE such as helmets, safety shoes, Nose Mask, safety goggles, rubber hand gloves etc.

civil techniques

Preventing water entering into water-bonding structures

abbu riyaz 30 Apr, 2023

Preventing water entering into water-bonding structures. Water leaking is the main problem occurring in many concrete structures. Mainly concrete structures like basement car parking, lift rooms, Tunnels, water leaking is the main problem. These leakages can repair and prevent in the concrete structures at the time of construction using chemical Admixtures.

Preventing water

Water leakage is becoming a serious issue in Underground structures nowadays. It makes serious impacts in concrete structures like,

Basement retaining walls
Parking structures
Concrete slabs
Tunnels
subway systems
Construction Joints
Foundations
Water retaining structures
Underground vault
Swimming pools
Sewage water treatment plants
Channels Reservoirs
Bridges
Dams and
Roads

Waterproofing carries out to prevent water entering into underground structures. We explain how to carry out this waterproofing process.

How to carry out waterproofing operation

After the construction of concrete structures & removal of shuttering, the concrete surface has to clean. And have an open capillary surface. Remove laitance, dirt, grease, etc, by means of high-pressure water jetting, wet sandblasting or wire brushing. Faulty concrete in forms of cracks, honeycomb, to be phase out and fill flush with mortar. The Surface to be carefully pre-water and concrete surface to be dry but not wet.

Application

Apply waterproofing chemicals like Crystalline waterproofing coating in one or two coats of masonry brush or appropriate power spray equipment. When two coats specify, apply the second coat while the first coat is still green. The specified amount of chemical admix like penetron, etc, it distributes in powder form through a sieve. And trowel into the freshly placed concrete.

ADVANTAGES

The Active chemicals react with moisture and by-products of cement hydration cause catalytic reaction that generates an insoluble, crystalline structure. Applying to the concrete surface, Crystalline waterproofing coating crystals fill pores and minor shrinkage cracks in concrete. And prevent water leakage at high pressure.

civil techniques

Self-healing joint Techniques for construction joint applications

abbu riyaz 30 Apr, 2023

In this post, we are explaining, how to avoid leakage problems in storage tanks, slabs, etc. By using self-healing joints techniques for construction joint applications.

Penebars use for building foundations, slabs, retaining walls, storage tanks, and other cold construction joints. It is a kind of unique sealing compound. And expands rapidly exposed to water. It is an ideal self-healing joint material for construction joint applications.

How to apply self-healing PENEBAR on poured-in-place construction joints.

1) Apply primer using a brush at a minimum of 0.1 x 25 mm wide over the surface.

2) Allow it to dry for 10-15 minutes, where the temperatures are low, allow it to dry for a longer time.

3) By using the heel of the hand and moderate pressure, press a bead of PENEBAR into position. Make sure the product has bonded to the primed area.

4) Splice ends to form a continuous, uninterrupted seal. Cut each end at opposite 45° angles and tightly butt ends together. Do not overlap ends.

5) Peel the protective covering from the exposed side of the installed PENEBAR.

6) Follow standard concrete placing procedures after this.

SPECIAL CONSIDERATIONS

Use Penebar Primer to ensure a tight fit.

Avoid movement of penebar.

For vertical surfaces, use nails with PRIMER to hold it in place.

If a Keyway is utilizing, place the Penebar into the bottom of the formed Keyway area.

On pipes and other structural penetration, cut Penebar to a required length. And placed around the penetration with ends butted. In all cases, Penebar is in direct contact with the substrate along the entire length of the installation. Penebar is not an expansion joint sealant. It is only suitable for non-moving concrete joints. Penebars not to installs in standing water. And in frozen or icy surfaces.

civil techniques

Using penetron technology to Increase lifespan of concrete structures by 60%

abbu riyaz 30 Apr, 2023

PENETRON ADMIX method is to protect concrete in most critical environments. PENETRON ADMIX becomes an integral part of the concrete. Easily mixed during batching and unaffected by climatic conditions & increase the lifespan of concrete structures by 60%.

PENETRON ADMIX performance highlights

Resists high hydrostatic pressure
Provides ‘self-healing’ capabilities for cracks up to 0.4 mm
Enhances the compressive strength of concrete
Non-toxic and contains no VOCs
Resists chemical attacks
reduces chloride penetration and carbonation
Effectively counters alkali-silica reaction
Prevents corrosion of reinforcement steel
Not a vapor barrier; allows concrete to breathe
Protects against sulfate attack.

Procedure

Add Ready-Mix Concrete PENETRON ADMIX at the batching plant.
Add PENETRON ADMIX to drum of the ready-mix truck.Add 60-70% of the required water along with 136-227 kg of aggregate.
Mix the materials for 2-3 minutes to ensure even distribution of PENETRON ADMIX.
Add the balance of materials to the ready-mix truck using standard batching practices.

The PENETRON ADMIX benefits

Increases durability and life-span of concrete by 60 years or more
Eliminates the need for any surface-applied protection systems
Saves money—lifetime concrete protection
Maximizes time on the construction site
Doesn’t require specific W/C or cement content to perform
Easy to mix into the concrete at batching.
Non-staining tracer ensures quality and performance
Soluble bag packaging eliminates measuring and simplifies mixing

How it works

Add PENETRON ADMIX to the concrete at the time of batching. This disperses the PENETRON chemicals homogenously throughout the mix.
PENETRON active ingredients react with water to form insoluble crystals, which fill cracks, pores, and voids up to a width of 400 microns. PENETRON ADMIX is an integral part of the concrete matrix; crystalline growth takes place throughout the concrete structure.
Water molecules (and harmful chemicals) can no longer pass through the concrete.
This avoids the buildup of vapor pressure.
In absence of moisture, the PENETRON components lay dormant. At any time, the sealing process resumes automatically, providing a fully self-healing concrete.