Demolition, Shoring, and Soundproofing in Construction
Precautions in Demolition Abatement
It is very important to study the structure. Dimensioning the cable is important because it can divide the costs. Instead of demolishing, cutting, and charging a beam. The cable resistance must be greater than the building. To this end, a backstop to distribute charges (in the wave barrier is placed metallic cable).
Security Mechanism: F1R > F2 > F demolition, being F1R carder breakage.
Key Features of Controlled Demolition by Blasting
It is more common, but you have to do a very thorough study of the structure to find and place loads. It has now been shown to be much more effective when all the points are operated simultaneously, but the charges have some delays. Demolition by blasting should always be done by specialized companies.
Difference Between Shoring, Underpinning, and Bracing
Shoring: It is always vertical (only transmits vertical forces). The charges have to be taken to the field, distributing them to the greatest possible surface. They are placed on wooden beams called sleepers at the bottom and race to the top. The vertical elements are called casing.
Underpinning: The slope (vertical and horizontal forces transmitted). They tend to be thicker to prevent sagging. The bending element is called depth. They are used when a wall is collapsing, horizontal thrust. The burden-sharing is carried out by the backstop. We have two rows of props, and we can pile caps. The charge is put in through the wedges.
Bracing: A horizontal element (transmit horizontal forces), prevents the approach of vertical surfaces. These elements are called struts. They are used in garages, ditches, underground car parks, etc. They can be temporary (ditch) and lasting (garage).
Definition of Foundation Underpinning
Underpinning is the action and effect of repairing the foundations of an existing building. Underpinnings are used to correct the pathologies of the foundations. Also performed when the foundation is not enough. It will be necessary to stress by: Default implementation, project poorly resolved, changes in areas surrounding the structure, changes in the assumptions under which the structure was designed.
- Increasing the bearing surface or increased shoe (open perforations and put steel bars, injected mortar and cover them with concrete, is made in small sections called bataches). If it is not sufficient to increase the shoe due to the terrain, they take the loads to the ground through micro-piles.
- If the field is in poor condition, it can be improved with a system called jet-grouting, which is drilling and injecting high-pressure cement slurry.
Conditions Which Scaffolding Must Meet
- Resistant: To all charges which have, by giving the necessary tension to compression.
- Stable: It depends on the constraints you have. If you are not connected with the building, scaffolding is called exempt.
- Safe: For all staff who work in them, elements of protection in the scaffolding, nets, rails, and baseboards.
Differences Between Simple and Assembly Scaffolding
Simple Scaffolding: They are built by the mason.
Assembly Scaffolding: In its construction, the carpenter is involved to assemble. They are stronger and perfect for being designed to withstand greater loads. They can be fixed or flyers. Types: mobile scaffolding, hanging, headgear, lyre, etc.
Requirements for Formwork
- That hold loads up to build the arch.
- Have the final shape of the arch, the arch play. If it is big it has to be calculated if small deformation and the arch and the centering is the same.
- That can be easily removed with the exception of autocimbra, which is within the arc.
- It should be readily disassembled so they can be reused again.
Superstructure of a Formwork: Components
It is responsible for playing the arch or dome are curved trusses recharge elements. It can be made of brick. It is supported by an infrastructure or felling. Between these two elements are placed descimbramiento. Formed by several trusses connected by a sheathing that gives the shape of the dome.
Procedures for Formwork Removal
The main procedures used in the descimbramientos are:
- Juxtaposed Wedges: This system consists of two wooden wedges used a very small angle to the decrease is very slow and not occur spontaneously under the weight of the formwork. It is very sharp and may fail, it is not reversible.
- Sandbags: Posts instead of the wedges hold the ribs in the required position. A hole and leave out the sand. We can not stop it, slow descimbramiento good.
- Litter Boxes: It is safer than the bags, is slow and can not be reversed but if we can stop it.
- Jacks: The best of all, we can stop descimbramiento at a given time and is reversible. Jacks, hydraulic and mechanical (screws).
- System triarticulated arches.
Difference Between Absorption and Sound Insulation
The interior must be borne noise and external noise must be isolated. The interior noise produced in the building is absorbed through felt pads placed on the floor and ceiling, cork, etc. The outside noise, are transmitted through the air, are separated by dense and thick materials.
Different Kinds of Noises
- External Noise: Airborne, penetrating inside the building. It is insulated with thick, dense materials.
- Interior Noise: Produced from within the building. We must avoid the resonance. This felt is used in the ceiling and floor, suspended ceilings (office), the steel is (do not absorb anything, and are very dense, resonators) and plaster (resonators reinforce its porosity).
- Impact Noise: Are transmitted through the structure. Footprints, plumbing lifts, etc.
Absorption Coefficient, Reverb, and Sound Insulation
Absorption Coefficient: As the ratio between the energy absorbed and the incident energy by a surface or substance. The absorption maximum is one, is not reflected nothing and absorbs everything.
Reverb: This is a phenomenon resulting from the reflection of sound, the sound is coming from different paths. If there is no reverb sound absorption.
Sound Insulation: Refers to the set of materials, techniques, and technologies developed to isolate or mitigate the noise level in a given space.
Resistance to Heat: Conductivity and Thickness
Different Types of Heat Transfer
It can be done by:
- Conduction: Transfer of particle is in contact with a body.
- Convection: Transfer between a solid and a fluid displacement of fluid particles, removed by external forces or by the tendency of hot particles.
- Radiation: Emission of heat energy that affect other body is absorbed by it. Not all energy is absorbed.
Bases of Thermal Protection
- Decreasing the permeability Thermal conductivity coefficients with small and larger thicknesses possible, reducing the value of it and reducing the value of “e”.
- Avoid thermal bridges: when we have a conductive element is simultaneously outside and inside the building.
- Avoid excessive air renewal.
- Accumulation of heat in floors walls and ceilings: for better temperature control of premises should have heat-absorbing materials.
Types of Damp
- Work Damp: They are due to water from the concrete part to hydrate the cement and a pin. They are totally unavoidable, negligible damage. Vented to eliminate them.
- Following Work Damp:
- Capillarity (is cancer of the buildings, caused by groundwater that bring salt that corrodes steel, also crystallize in porous rock, lack of study in the project, broken pipes).
- Infiltration (enter through the building through cracks, windows, they are mainly covered by construction defects).
- Condensation (when the water vapor in the air exceeds a certain amount and confirm this is lower the lower the temperature, venting is eliminated or increasing temperature).