Construction Cost Estimating

      

Foundation Problems and Solutions

Given below are the reasons which will guide you to find the issues in foundation.

When the floor separates from its floor leading to bumpy or descending floor,if you find there are cracks in the bricks or blocks of a wall, in case of cracks in the ceiling decorations or moldings, when you can spot a swelling exposure of a part of wall or noticeable split or separation in a continuous wall, when there is an overlapping of cracked wall parts (this crack is usually seen on wall which lies between the door frame and ceiling), when there are cracks in steps / floor / floor tiles, cases in which you can’t open or close the door / window properly and separation between door/ window frame & wall.

NOW LET’S CONSIDER WHAT REASONS MAY CAUSE FOUNDATION DISTRESS?

Foundation distress can be caused by contents which is present in the soil, can also be caused by compression or expansion in soil, improperly compacted soil, it can be the result of natural disasters like earth quake, sudden exertion of artificial forces or poor maintenance can lead the foundation structure to repair.

Also, with uneven movement among the soil layer which takes place after the settlement of foundation structure can also cause the damages as, the foundation structure rests on soil layer.

Now let’s land on the main part of the article that is types of foundation repairs.

SEALANTS IN FOUNDATION REPAIR

Even though regular maintenance is encouraged, the simple or minor cracks can be treated with masonry patches or sealants.

For minor cracks these are sealers which are used in the construction industry- Hydraulic cement ( which is a lot like cement mortar and can set very fast with respective to time) or epoxy (which is similar to paste and can be found in a variety of viscosity as to use various width of cracks) or polyurethane ( it is a good sealer and can set fast). This step must only be taken in case of minor cracks.

SLAB JACKING OR MUD JACKING IN FOUNDATION REPAIR

Previously the sunken slab which is raised by filling mud under the slab or even by filling concrete mixture under the slab using hydraulic pumps. In recent time, the hydraulic pump is replaced by a trailer which consists of polyurethane system.

This trailer can carry the amount of cube required, along with portable hydraulic slab-raising pump, also with concrete mixer and time duration for the cleaning process of the machine which is eliminated in the new process as there is no requirement for heavy equipment for example concrete mixer and therefore requires less time to clean the equipment.

What happens in the slab jacking process by concrete mixture or mud mixture is that the mixture is poured into a concrete mixer wherein water and additives are added. To the portable pump the final mixture is shifted after which the pump can be moved to the required location.

Ultimately, using the hoses the mixture can be pumped into the drilled holes. The mixture must be refilledwhen the pump is empty. A number of steps can be eliminated in slab jacking process by polyurethane. Here, the only thing that is required is the injecting of the foam into the holes when needed. Kept in the trailer is the two liquids which can react to get the desired foam are stored apart.

The injecting gun which one end is attached to the hose is inserted into a hole to pump out the foam this takes place after the holes are drilled. Within a little period of time the foam expands its volume by nearly 25 times and it then sets to a rigid material. The polyurethane foam slab jacking is little costlierthan to mud or concrete slab jacking.

A more usual process is the slab jacking which is used to regain the position of sunken concrete by pumping cement mixture & other additives. It must be noted that slab jacking is not a simple task as it needs professionally specialized equipment, knowledge and persons. With the usage of portable equipment such as pump and hoses the cement mixture will then be able to pump into the tactically drilled holes on the existing concrete structure.

ADVANTAGES OF SLAB JACKING

The old base is strengthened by the new concrete mixture. In comparison to the need to replace the whole structure the cost required for slab jacking is low. The place where slab jacking has been done can be used within hours. There is no wastage and sound pollution in comparison to the replacement of a new structure.

Given any weather condition this method is extremely suitable. No cleaning of space is required as this method can never ruin the place when compare to the rest. There is no chance for colour change in the structure due to the fact that the new concrete mixture spreads beneath the old slab layer.

The problems involved in this method is, excessively pumped concrete mixture or thin concrete mixture may lift the structure on a wrong place or tends to form new cracks or enlarges the old cracks.

PIERING OR PILING IN FOUNDATION REPAIR

In this technique, steel or concrete piers is used to resettle the foundation. There lies a little difference between piering and piling technique. By just excavation piering can be done whereas piling must be done by driven piles into the ground. Some varieties of piering or piling includes- concrete pressed piling, steel pressed piling and bell bottom piering.

STEEL PRESSED PILING

IPiling piers and Piering helical piers are the two ways to work in this category. Piling piers is galvanized or coated steel pipes are driven into the ground with the help of hydraulic ram and piering helical piers is galvanized or coated screw piles with steel shafts are used to here.

A trench should be dug around the foundation and when the steel pile reached a suitable stable point, the hydraulic jack is used for bring the foundation back to its normal position, this process must be followed for installation. Ultimately, the steel shaft attached to the pile is fixed to the foundation by bolting or welding.

ADVANTAGES OF STEEL PRESSED PILING

The advantages include how the steel piers can press deeply into the soil and can therefore provide a firm attachment to the soil. The installation cost of steel piers is low. When compared to concrete piers the steel piers can withstand more heavy weights.

CONCRETE PRESSED PILING

First you have to drill holes on the structure which is in need of repair to a deep depth. After which the next step is to fill the hole with reinforcement and concrete. At times precast concrete piles are used, in which case you must never use any reinforcement.

ADVANTAGES OF CONCRETE PRESSED PILING

  • Low in cost
  • Heavy equipment is not required
  • Tactical skills not much required as in the case of slab jacking method.

BELL BOTTOM PIERS

Here a shaft in the shape of bell drilled in to the foundation structure and then the space after the belled shaft is removed will fill with reinforcement and concrete.

ADVANTAGES OF BELL BOTTOM PIERS

  • Provides good strength
  • Due to the shape of the bottom, movement is prevented in the piers within soil layer.
  • Curing of piers before completion of project is required when in comparison to the rest.
Foundation Problems and Solutions
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