Brickwork (1:6) cement mortar in foundation plinth (Specification)

Bricks

Burnt clay bricks shall conform to the requirement of I.S. 1077-1957. The brick shall be of first class quality has been referred as local chimney made bricks. Bricks shall be uniform deep red, thoroughly burnt, regular in shape and size and shall have sharp and square edges and parallel faces to ensure uniformity in the thickness of the course of brickwork.

Bricks shall be free from cracks, chips, flaws, stone or lump of any kind. They shall be free from salt which effect the mortar of the masonry. Brick shall not show any sign of efflorescence. They shall be sound, hard, homogeneous texture and emit clear ringing sound on being struck and water absorption shall be minimum. Any bricks not up to the specification shall be removed from the site. Bricks shall not be dumped at site. They shall be stacked in regular layers even as they are unloaded. Bricks selected for different situation for the use shall be stacked separately.

Laying of bricks for masonry

Bricks shall be laid on a full bed of mortar evenly applied on the wetted surface of the brick work. If any dirt or earth is on the wall they shall be cleaned by wire brush and wash down with water jet. When laying, the bricks shall be slightly pressed so that the mortar can get into all the pores of the brick surface to ensure proper adhesion. Cross joint and wall joint shall be flushed and packed with mortar so that no hollow spaces are left. All brick work shall be in plumb, square and true to dimensions as shown in drawing. All brick work shall be built tightly against columns, floor ,slabs or other structural parts.

Cement

Cement shall conform to I.S. 269-1976. The weight of ordinary Portland cement can be taken as 1440 kg. per cu.m and rapid hardening Portland cement as 1210 kg. per cu.m. The measurement of proportion of cement should normally be on basis of weight and whole bag and scaled 50 kg.

Tests

The test of brick is necessary as specified in I.S. 269-1958.

Storage

Cement required for use shall be fresh as possible and stored on planks raised up to 15 to 30 cms. above the story away from the walls of weatherproof building in such a way to prevent deteriorations  by dampness or moist.

Foundations

Foundation is the lowest part of any structure. Most of the structure comprise of two parts. The upper part lies above the ground, the lower part buries under the ground . The upper part is called superstructure while the lower part is called sub-structure. The foundation is the interface between the superstructure and the underlying soil .Hence the foundation can be considered as a medium which receives the load from the superstructure and transmit it to the subsoil underneath.

The bottom of the foundation shall be leveled both longitudinally and transversely or stepped as directed by the Engineer. Before footing is laid final surface shall be slightly watered and rammed. No filling shall be allowed to bring the foundation to level. All rock or other hard foundation cleaned of soft or loose material.

After each excavation is completed, the contractor shall notify the engineer to that effect and no footing shall be allowed to laid.

Disposal of excavated materials

No materials excavated from foundation trenches of whatever kind they may be, are to be placed even temporarily nearer than 1.5 meters or greater distance. Rate for excavation includes sorting out of useful materials and stacking them separately as directed.

Dewatering

The excavation rate shall include pumping out all water. Pumping water from any foundation enclosure or trenches shall be generally in such a manner to preclude the possibility of damage to the foundation.

Back filling

All timber work and form work shall be removed after their necessity ceases. All space between foundation masonry or concrete and the sides of excavation must be refilled to original surface with approved materials.

Rate

Ø  Cleaning site

Ø  Bailing and pumping out water

Ø  Backfilling the trenches alongside masonry or concrete with approved material up to the natural ground level

Ø  Small drill holes to explore the nature of sub soil if necessary