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Rubblework. STRUCTURAL RUBBLEWORK -
CONCEPTS
They presented already the general approaches on the structures and the
projects, we enter to understand the Mampostera Structural, enunciating its
components, characteristics, advantages and limitations. We recall that the
brick of clay is the first material created by the control of the human
intelligence on the four elements: the land to manufacture it, the water and the
air to knead it, the air to dry it and the fire to cook it. On the other hand,
thousand-year-old works of the history of the humanity go they last and they
were built in stone, today in good part replaced by the concrete one, in which
the paste of cement and water ties and consolidates the stones pequeas and
grains of sand for. Constituting a piled up artificial very seemed to some
natural stones. It mentioned al principle of these notes the need to know the
"why?" before learning the "how?" I reiterate this affirmation because badly it
could to apply a structural system if it not the characteristics individual of
his components are known and what cannot contribute to the solution structural
each one of them. In ours fear, the Mampostera Structural, we can identify the
following components:
1) Block: - Contribute Structural: * Capacity to
resist you charge vertical (resistance to the compression), - Other contribute:
* Cerement, divisions, finished end, esthetics.
- Characteristic necessary:
* Resistance to the compression
* Low permeability
* Uniformity in dimensions
* Low absorption
* Low
* Shrinking before permanent loads
*High resistance al wears
2) Mortar of Hits:
- Contribute Structural:
* Union of blocks
* Resistance to the compression
- Other contribute: * Impermeability
* Esthetics - Characteristic necessary:
* Good plasticity to permit the manual management
* Uniformity: Content of sand and cement. Granulometry of the sand.
* Impermeability, facilitated by addition of lime.
* Resistance to the equal or greater compression that that of the
Blocks.
*Good capacity of retention of the water while complies the process of
moisturizing of the cement.
3) Steel of Vertical Reinforcement:
Structural Contribution: * United with the block by means of concrete of
filling, it contributes the resistance to the flexion generated by horizontal
forces (earthquakes, winds, etc.)
4) Steel of Horizontal Reinforcement:
- Structural Contribution:
* Resistance to horizontal sharp efforts.
* Control of figuration by changes of temperature.
* Mechanical connectors between walls, without ties in the corners.
5) Mortar of Injection:
- Structural Contribution: * Entailment of the steel of vertical reinforcement
with the blocks.
* Increase of areas effective of the section of the wall to support horizontal
sharp efforts. - Characteristic necessary:
* It is a fluid concrete mixture to fill cavities, without undergoing
segregation of his components. * High plasticity to allow the drained one.
* High establishment.
* Sufficient humidity so that when making contact with enemy by porous surfaces
of the rubblework it is not solidified by the water absorption conducted by the
walls of the rubblework cells.
6) Plates of entrap: This type subject is valid for any structural system,
but due to his importance it is necessary to mention it now. The functions or I
contribute structural of the aerial plates of entraps are: a) to support
vertical loads and to lead them towards the support walls.
b) Distributing the horizontal forces (of wind, earthquake, or establishment),
between the support walls. This distribution is made according to the
characteristics of the plate, thus: - If she is very rigid, horizontally, it
distributes them to the rigidity in proportion of the walls. - If the plate is
flexible, horizontally, it distributes them wall in proportion to the afferent
areas to each of support.
7) Layings of foundations: Also
this subject is valid for any structural system but it is included because it
complements the list of components of the structural rubblework construction.
Their contributions are:
a) To transmit the loads to the lifting land.
b) Bond between the structure and the land, for the denominated interaction
structural ground when arriving the seismic movement. For the case of the
structural rubblework, the loads arrive at the laying of foundations in form
uniformly distributed throughout the walls of the first level. This
characteristic generates the necessity to take these loads by means of few
alternatives from lying of foundations, thus:
- "In excess" Laying of foundations or Shoes: that is to say, of dimension it
uniforms all along of each wall. The wide one of the foundations depends on:
* The magnitude of the vertical loads.
* The terrain featureses of lying of foundations:
- Lifting Capacity
- Compressibility (establishment).
Other circumstances of the land can force to construct sub-bases underneath the
foundations. This can be of concrete Cyclopes, concrete simple, Be accustomed
to-cement, or, inclusively, a pilotage system.
- Continuous Foundations: that is to say, laying of foundations plates that
occupy all the projected area of the construction, normally recommended when the
lifting capacity of the land is very low, or when its compressibility is very
high (risk of excessive establishments). Also it is common that under the
continuous plate of laying of foundations it is constructed sub-bases, either by
necessity to obtain a level determined in first stage, or because it is
necessary to replace the superficial land.
8) Covers:
The structural system of cover is of special importance in the Structural
Rubblework. Generically, from the point of view of contribution to the
structure, the cover can be:
a) Plate: in this case the differentiation given for the plates of enterprise is
applicable, between rigid and flexible. |
