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 the placing of the blocks is of relevance, as there will be significant differences in block manufacture. For this reason, the following recommendations are advised:

• - blocks should be dampened before being laid to avoid drying out the mortar, except under the express instructions of the manufacturer for blocks which have a low absorption rate (absorption [ 0,10 g/cm2 · min]).

• - blocks should be laid on the vertical joint without mortar, making a fished joint between the tongue and groove joints.

• - the vertical fit of the blocks should be appropriate, according to the specified criteria at point c of section 5.2. When this is not possible, due to the geometry of a certain block, that particular block should not be laid and should be replaced with another one. Nor should broken blocks, or those with cracks greater than that specified in point b of section 5.2 be laid.

• - in order to achieve an adequate attachment of the brickwork, both in supporting walls and enclosures, the distance between the vertical joints of two consecutive courses should be a minimum of 7 cm.

• a). in enclosures or external walls, lay the horizontal joint in sections by spreading the mortar in two continuous strips separated by 1 or 2cm at most, except for the first joint on each frame, which should be continuous.

  to achieve this separation and the appropriate thickness, use a section ruler of 30 x 50 mm, by placing this on the centre of the course.

  on enclosures or external walls where the improvement of mechanical (a characteristic of the brick being resistant to pressure) or acoustic (insulation of airborne noise) features are required, a continuous joint may be considered, keeping in mind climatic conditions and the exposure of each façade.

  for both types of joint, whether continuous or interrupted, in the case of exterior walls in poor condition (for example, on north-facing facades and in cold areas), in order to avoid the risk of interstitial condensation, special attention should be paid to conditions of use and the interior environment.

  if the wall or exterior enclosure is backfilled, the horizontal joint can be continuous.

• b). on interior walls, the horizontal joint should be continuous.

  · when making both types of joints, whether interrupted or continuous, it is important to place a sufficiently thick layer of mortar (approx. 3 cm) in a way that, once the block is correctly placed, the resulting thickness is between 1 to 1.5 cm.

  . once the mortar has been placed, lay the blocks vertically and bed them in with a rubber mallet. Never rub them in as you lay them.

  · on walls and exterior enclosures, always to place the edge of the block on deep furrows facing outwards.

  · once the mortar in the joints has lost its elasticity, it will not be possible to correct the alignment of the blocks.

  · in line with that indicated in section 3.2, use complementary pieces and cut pieces to complete specific points.

  · when the use of cut pieces is required, do this following the recommendations in section 5.10 “Cutting the blocks”.

  · the vertical joint of base made with cut pieces should be made with lines of mortar. See section 5.9 “Dimensional adjustment.

  · use a mortar which is suitable for the characteristics of the block and appropriate for its intended use, according to the manufacturer’s instructions or, otherwise, the Termoarcilla® Consortium. See section 2.3 “Mortars for bedding joints”..

  · out of every 100 blocks laid, one should be removed to check the correct placement of the horizontal joint.

  · in order to ensure that stresses caused by the shrinkage of the concrete do not produce horizontal cracks in the wall, the following criteria should be considered:

    - when the frame requires shoring, it is important that the minimum amount of weight is transposed onto the supporting walls.

    - if the floor slab used does not require shoring, it would be convenient to leave the wall to harden before subjecting it to a load. The minimum time for this will depend on the type of mortar and the environmental conditions (approximately 1 week at temperatures of between 15º and 20º C).

    - for exterior enclosures, we recommend that work begins at the top floor of the building so that when each floor is enclosed, the adjustment in the above floor slab has already taken place. If this is not possible, the enclosing of alternate floors is recommended.

• a). origin.

    · all blocks and complementary pieces used in a construction should originate from a single manufacturer.

    · if the proposed solutions have to be built using pieces manufactured by different companies of the Termoarcilla® Consortium with DAU documents, the evaluation of compatibility between the pieces to be used (geometric, mechanical and physical characteristics) will be required.

• b). cracks and breakages of the pieces.

    · definitions considered:

      - cracks: this refers to more or less irregular fissures which affect the total thickness of a wall or partition of a block.

      - cracked piece: a piece with one or more cracks with a length of 20% or more of the affected surface (length, width or height) on some of its exterior walls or internal partitions.

      - aspect levels:

        level I: in a sample of 6 pieces there is a maximum of one cracked piece.

        level II: in a sample of 6 pieces there is a maximum of three cracked pieces, of which only one may present cracks on external walls.

    · within the DAU document, each manufacturer should declare the aspect level of their pieces.

    · if the construction pieces received for use on supporting walls are below the specified* levels, they should be replaced by other pieces which conform to the criteria. On no account should blocks be laid that have fissures or openings equal to or greater than 1 mm.

    · broken pieces arriving on site should not be laid (whenever possible, they can be used for obtaining cut pieces).

• c). fit and alignment of pieces.

    · general criteria:

      base or complementary pieces should not be laid if they do not align. That is, if for any geometric reason, the interlocking tongue and grooves do not line up

      when making the bond, pieces should not be laid if their vertical joint alignment does not close at either of its extremities, whether this is due to the extremity or due to the fit of the tongue and groove.

      if, once the blocks have been laid, there is any unevenness greater than 5 mm between their edges the brick surface will require smoothing with mortar before covering the wall.

    · specific criteria:

      according to the DAU 004 Trials, Trials for fit and alignment of tongue and groove bricks. Lightweight clay block, the pieces should comply with the following conditions, which have been laboratory tested according to the trial specifications indicated in the above document.

· no materials other than Termoarcilla® should be used for the completion of the wall or enclosing any of its points, except in those cases where the contrary is indicated within this document. See section 3.1.1.3.

Both in supporting walls and enclosures, fix leaded levelling poles with all their surfaces at right angles, at distances of no more than 4 metres apart, and always in every corner, gap, fracture or moving joint.

mark the vertical spacing on the levelling poles, as well as the levels of the railings and the lintel levels in the gaps.

before laying a course, place a lightly-tensioned line between the corresponding marks on the upper angles to serve as a reference point for correct laying.

on closing walls, the surface will be defined by taking the slab with the greatest surface area as the reference point. Set counterweights that drop from the top floor to the ground floor with marks at each of the floors in between. Leave the reference points in place so that the defined plan can be reconstructed at any time.

given that vertical mortar joints do not exist, and that there may be differences in the length of the blocks due to the dimensional tolerance of the pieces and/or variations in the fit between them, the different courses may require different pieces to resolve this. For this reason, the layout of the brickwork is reduced to the placement of levelling poles and counterweights.

take the highest point of the slab or cement as a reference for level, and use the necessary thickness of mortar under the first line to compensate for any deficiencies in level.

mark the vertical spacing indicating the slab level, as well as those for guarding walls and lintels in the gaps.

adjust the spacing by varying the thickness of the mortar joint (between 1 and 1.5 cm) and use vertical adjustment pieces or base pieces. Cut these with the appropriate tools (see section 5.10).

in general, the use of traditional bricks (perforated or hollow) for the adjustment of wall height is prohibited. Nonetheless, perforated brick which is equal to, or more resistant, in pressure than the Termoarcilla® block can be used, placed in those sections of wall situated in uninhabited areas (such as basements or roof spaces).

• basic principles

  1. maintain the ties, making the distance between the vertical joints of the consecutive course layers greater or equal to 7 cm (see section 5.1 “Placing the blocks”).

  2. use complementary pieces in specific places (corners, posts in gaps, movement joints, where T walls meet and other points, as indicated in section 3.2).

  3. use the least number of cut pieces possible to adjust the length of the wall as defined in the plans.

  4. place the blocks by linking the longitudinal tongue and groove.

• basic criteria

  depending on the means available (installers and scaffolding equipment), the brickwork can be raised throughout the whole perimeter or extension of the building, either by walls or by wall sections. If at any point, due to organisational needs of the build, it is necessary to interrupt the brickwork in one section, instead of doing this at the end of a wall (for example: at a jamb or an movement joint), scale the brickwork as, unlike traditional brickwork, it is not possible to leave toothing and indenting blocks in place.

  if the walls are built in sections or facades, in the corners or meeting points between walls, the adjacent sections should be scaled and prepared for later building work. In this case, the laying of more than 5 or 6 courses is not recommended

  once the levelling poles are in place, mark the reference points out and place the corresponding string line, each course should be laid following the steps below:

    1. place the complementary pieces that define the ends on the wall section to be laid (corner, end or middle).

    2. place the corresponding pieces at the specific points identified in the wall section to be laid (gaps, movement joints, where walls meet, where walls meet pillars, etc.).

    3. place the blocks that fill the space between the pieces as indicated in 1) and 2), keeping the following aspects in mind:

      - keep checking the gaps between the vertical joints on consecutive courses.

      - if at any point the gaps between the vertical joints are less than 7 cm, place spacing pieces, cut pieces and/or two lines of mortar in order to recover the section within the smallest space possible.

  keep in mind that the insertion of a stretcher into pieces of less than 30 cm (cut piece or spacing) into the structure of a wall may lead to a loss of more than 7cm in the gap between the vertical joints.

  - whenever possible, try to avoid the loss of ties between courses of the same vertical area within an area of the brickwork. In order to avoid this, particularly where it is necessary to cut pieces or use spacing pieces, carry the adjustment over horizontally into successive courses. Another useful solution, although not required in all cases, but in situations where a loss of attachment is produced on the same vertical layer, use reinforcement in the joint.

  - when using cut pieces or a very small dimensional adjustment is required, use a vertical mortar joint according to the conditions in section 5.9.

  - using more than 2 vertical mortar joints per course, and per section of brickwork, is not recommended. It is worth emphasising the advantages of using spacing pieces as opposed to cut pieces, particularly when they are being used to recover the attachment. As these pieces do not require the use of vertical mortar joints, they reduce need to cut pieces and they improve work output.

for aspects that are not defined in this document, Eurocode 6, Parts 1-1 and 2 can be used for reference.

acceptable sag on the slab surface in the case of enclosures.

the maximum acceptable sag on the surface of a slab is the same as for traditional brickwork. Applying the values established for walls by the basic building standard, NBE FL-90:

· sag: 10 mm in the height of each floor and 30 mm in the total height of the building (in the case of buildings with two floors, it should not be more than 20 mm). If at any point, these values are greater than the maximum acceptable values, in order to absorb the difference, fixed profiles could be attached to the surface of the slabs, but only when the construction environment is not in a maritime climate or in industrial areas with harsh environments (see section 3.2.15.2).

· when the length of the course of blocks needs to be adjusted to that of the wall or enclosure on a horizontal level, use either spacing pieces or cut pieces.

· if using cut pieces, the vertical joint can be resolved with two bands of mortar of a 6 cm £ width £ , 1/3 the width of the block, in order to correctly transmit the horizontal stress on the wall surface.

the central space that remains hollow between the bands of mortar could be filled with an insulating material, like expanded polystyrene or glass wool. This will improve the thermal effect of the wall and will avoid the need to fill the vertical joint with mortar.

the vertical joint should have a maximum gap of 2 cm from the end of the tongue and groove. If the existing slack is greater, it will need to be distributed among various vertical joints. This joint can also be used, in a limited way (a maximum of 2 joints per section of wall), to make minor adjustments of up to 2 cm.

on curved walls, this can be used with the criteria indicated in section 3.2.11.

· on no account should horizontal adjustments be made which open the vertical joints, by placing mortar fillings (only mortar joints such as those indicated in the previous point) or by using ceramic materials that are different to Termoarcilla®.

· when it is necessary to adjust the vertical spacing, this can be done by using pieces of vertical adjustment and/or by varying the thickness of the horizontal joints between 1 and 1.5 cm. Pieces of other ceramic materials which are different to Termoarcilla® should not be used, except in cases indicated in the fourth point of section 5.5.2 “Vertical layout”

nonetheless, compression-resistant perforated brick can be used if it is equal or superior to the Termoarcilla® block placed in that section of the wall, and is situated in uninhabited areas (such as basements and under roof spaces).

· for external enclosures, we recommend using the vertical adjustment piece to lay the last course under each slab.

· the vertical adjustment pieces can be obtained by cutting on site, as long as the appropriate methods are used (see section 5.10).

the blocks should be cut on site with a table cutter using the appropriate diameter disc.

blocks should not be cut using manual methods.

if a cutting table is not available, the pieces should be cut with a power cutter. In this case, vertical adjustment pieces should be supplied by the manufacturer.

characteristics of the table cutter with vertical disc:

  · length of cut: 600 mm

  · depth of cut: a minimum of 200 mm

  · disc diameter: a minimum of 550 mm

to avoid the appearance of horizontal cracks due to excessive shrinkage of the slabs, it is necessary to observe the following parameters:

  · Water/cement relationship (higher relationship can produce excessive shrinkage).

  · Granulometry (the finer grain sizes increase shrinkage).

  · Type of cement used.

  · Curing (it is important to cure the cement correctly).

this problem becomes more noticeable in the corners. For this reason, it is recommended that the main walls of the building are thick enough.

avoid long sections of concrete. If this is required, lay the concrete in alternate sections (leaving a sufficiently long period of time between adjoining sections) or make the sections independent of each other by using movement joints.

- from rain:

cover with plastic and avoid the mortar getting wet, erosion of the joints and the accumulation of water inside the wall.

- from frost:

during frosty weather, inspect the brickwork at the beginning of the working day. Avoid laying brickwork during periods of frost.

if it is frosty at the beginning of, or during, the working day, protect the brickwork with insulating or plastic covers.

- from heat:

keep the brickwork damp to avoid the rapid evaporation of the water from the mortar.

· if the brickwork is interrupted when walls are laid at different time periods: leave the wall scaled at the starting end (do not leave any toothing or indenting stones).

· shore up the walls during construction to avoid them collapsing due to unforeseen actions (wind, etc.).

· in order not to crush the mortar, do not lay an excessive height during a day’s work (do not exceed one floor or 3 m).

the impermeability to water of the Termoarcilla® wall is achieved with the exterior covering. For this reason, its correct application is of the utmost importance

the conditions for applying the chosen coverings are:

· for a single layer of mortar, follow the instructions in the corresponding DIT or DAU.

· for a single layer mortar of lime and cement, follow the manufacturer’s instructions.

· for plaster, the instructions in the NTE-RPE-1974 Wall coverings. Plasters, which should be confirmed with the manufacturer of the paint applied.

· for paint, follow the manufacturer’s instructions.

with single layer mortars, apply a prior fine levelling layer with the same mortar, except when the application of the single layer is applied with a projecting machine (following the ANFAPA recommendations). If the brickwork contains similarly uneven areas which are greater than 5 mm, the brickwork surface will require levelling out with mortar before applying the single layer covering.

in these mortars, as in the plasters considered (for which it is also recommended), use wire reinforcement at the points where stress is concentrated and which may crack the covering layer:

· changes of wall section or enclosure.

· areas with potential pressure next to horizontal movement joints.

· angles at the top of openings and gaps.

· meeting points with pillars in enclosures.

· curved walls.

· areas where it has been necessary to level out the butt joint of the blocks with mortar, particularly in cut pieces. .

at those points where it is necessary to place trusses in the bed joints, the following should be kept in mind, according to section 5.2.2.4 of Eurocode 6, Part 1-1:

· the minimum thickness of the mortar covering from the truss to the face of the brickwork should be 15 mm.

· the mortar covering, above and below the bed joint truss should not be less than 2 mm.

· the truss should be placed in such a way that its whole length is covered.

the cut ends of all bars, except those made of stainless steel, should have a minimum covering, which is equal to that established for unprotected carbon steel, in the exposed position considered (Eurocode 6, Part 1-1, table 5.2), unless other means of protection are used.

the walls should work on basic compression, avoiding excessive horizontal pressures, bending away from the wall plane, strong eccentricities of loads or local traction.

in general, the mechanical capacity of a load-bearing wall which depends, among other parameters, on its thinness, will improve if it is conveniently joined at the ends to the slabs and to other walls which will shore it throughout its height.

avoid elements of walls which are excessively thin, and which may encounter problems with stability.

the distance between the axes of shoring walls should be a maximum of 8 cm, the same as for the rest of the brickwork. Its minimum free-standing length (without including the thickness of the shored walls) should be 0.2 times the clear height above floor level, and its dimensions should be checked through calculation.

· slabs should be created according to EFHE and EHE instructions

· warping limits:

the total warp over time should not exceed the lower of the following values: L/250 and L/500 + 1 cm.

the active warp should not exceed the lower of the following values: L/500 y L/1000 + 0,5 cm.

· in the union with the slab, there should be reinforced concrete ties placed within the thickness of the actual wall. Joint solutions should be applied which increase the edge of the tie in respect of the slab. Alternatively, joint solutions can also be used without increasing the edge of the slab. In either case, an overlap splice can be applied by including or inserting the overhanging armature.

- in the first case, the following value is recommended for the edge of the tie:

cz = c + 5, where: cz edge of the tie

the purpose of increasing the edge of the tie is so that it does not interfere with the armatures of the beams.

· width of the tie:

- if this is an exterior wall, the width of the tie should follow the values below:

az ³ 2/3 t

az ³ 14 cm, where:az thickness of the tie, t thickness of the wall below it

- if this is an internal wall, the width of the tie should be equal to the thickness of the wall below it.

· the settling differences in the cement between every two points should be as small as possible, and their separation should be no greater than 1/500.

· the base of the continuous footing of a wall should always be horizontal and situated on one single plane whenever possible. When this is not possible, use formworks to distribute it evenly.

· if cementing with isolated footings or piling is required, place these between joint beams of the appropriate dimensions to flex and resist the load of the walls, in a way that will not cause any relative deformities greater than 1/500 or 1/1000+0.5 between two points.

· the minimum length of the buttresses should be 45 cm 20 , available as 1 and a half pieces.

· in load-bearing wall structures with seismic acceleration coefficient values: 0.06 £ ac /g £ 0.12, the information indicated in chapter IV of the NCSE-94 should be followed:

- the distance between gaps should not be less than 60 cm

- the distance between a gap and a corner should be greater than 80 cm

· if it is necessary to substitute a load-bearing wall with a beam supported on pillars and pilasters, the pillars should be a minimum of 45x45 cm 21 .

the pilasters should be a minimum width of 45 cm 22 . The pillar solution should not be used in buildings situated in areas of seismic acceleration with a coefficient equal to or greater than 0.06 g, in order to avoid important differences in rigidity in both floor directions.