build tech

• PALEOLITHIC ( Old Stone Age ) they were nomadic hunter and lived in a cave
• Mesolithic (MIDDLE STONE AGE) they were food gatherer, had temporary shelter.
• NEOLITHIC ( NEW STONE AGE) they were farmers and had permanent settlement ( had communal houses).
• Tent - wooden poles/animal bones as framework and leaves to form the tent.
• HUT - broad leaves intertwined as covering, clay and wood were used, and reeds padded with clay for walls.
• COMMUNAL HOUSE - wooden post and lintel to support the ridge pole and rafters. Thatch for the roof and walls were made of clay, wattle and daub, tree bark.
• STONE STRUCTURES - dolmen, granaries, temples, cromlech
• Example of cromlech is the STONEHENGE which is a circular arrangement of megaliths enclosing a dolmen.
• AASHTO Soil Classification System:

  • Classifies inorganic soils for suitability as subgrade materials in terms of good drainage and bearing capacity
• Atterberg Limits:

  • Liquid Limit (LL): moisture content at which a soil changes from liquid to plastic state
  • Plastic Limit (PL): water content at which a silt or clay material will begin to crumble
  • Plasticity Index (PI): range of water content over which sediment behaves
• Fill materials:

  • Soil, crushed stone, and sand used to raise an existing grade
• Granular Fill or Filters:

  • Soil materials with sand equivalent of not less than 50%
  • Used to prevent the movement of fine particles out of soils
• Borrow Fill:

  • Selected laboratory-approved pit-run gravel, disintegrated granite, sand, shale, cinders, or similar materials
• Base Course Materials:

  • Hard durable fragments of stone and filler of sand or mineral matter
• Riprap (Rock Lining):

  • A constructed layer or facing of stone to prevent erosion
  • Riprap gradations range in diameter from 50mm to 1148mm
• Wire-enclosed Riprap:

  • Consists of mats or baskets fabricated from wire mesh, filled with small riprap, and anchored to a slope
• Geosynthetics can be categorized into different components:

  • Geotextiles
  • Geomembranes
  • Geocomposites
  • Geonets and Geocells
• Geotextiles are commonly used for reinforcement, separation, filtration, and in-plane drainage in civil engineering

  • Reinforcement: strengthens low load-bearing soil to increase overall design strength and reduce the need for sub-base and base course material
  • Separation: prevents migration of materials between different layers
  • Filtration: stops the movement of fine particles in soil where seepage occurs
• Geotextiles are also used for subsurface drainage applications, erosion control, sediment control, and in-plane drainage
• Geomembranes are impermeable polymeric sheets used in ground applications

  • Types include thermoplastic products like high-density polyethylene (HDPE) and polyvinyl chloride (PVC), and thermoset polymer like Ethylene propylene diene monomer (EPDM)
• Geomembranes have significantly different properties including strength, longevity, resistance to ultraviolet light, thermal expansion and contraction, chemical resistance, and ease of installation
• Geomembranes should not be subjected to tensile stresses and should be treated gently during installation and subsequent use
• Geocomposites consist of a combination of geosynthetic components and are usually sheet or edge drains consisting of a prefabricated core to which a geotextile filter is bonded
• Geocomposite sheet drains have a core that provides void space for water flow in-plane while the geotextile filter prevents soil from filling the voids
• Geonets are a type of geosynthetic with continuous polymeric ribs that form void space for in-plane flow capacity
• Geocells are three-dimensional prefabricated polymeric systems that are collapsed for delivery and then spread open and filled to form a three-dimensional reinforced mattress
• Geocells were originally developed to stabilize soft subgrades quickly and are now used for protection and stabilization of steep slope surfaces and protective linings for channels
• Temporary erosion protection materials include open mesh polymeric systems, biodegradable mesh systems, or a combination of polymeric and biodegradable mesh
• Open mesh systems serve as semi-permanent mulch to anchor seeds and soil particles subject to erosive flows in channels
• Termite proofing methods include physical barriers, chemical barriers, and Colony Elimination (Bait) System
• Physical barriers for termite proofing include Termite Resistant Sand and Termite Mesh used in slab construction and to wrap pipes and access areas
• In high-risk termite environments, homes are sometimes designed on high concrete pillars to physically separate the home from the distance termites can travel from their colony
• Chemical barriers for termite proofing aim to establish a continuous termiticide barrier or treated area between potential soil access routes and the structure to kill or repel subterranean termites
• Termiticide is a chemical used to control termites
• Pre-construction chemical barriers are applied during construction to the soil and foundation
• Termite resistant building products, from drywall to floor joists, are often treated with borates before use in home construction
• Chemical barriers can be vertical or horizontal
• Vertical barriers are created by applying 4 gallons of termiticide per 3 linear meters by rodding or trenching around the base of foundations, plumbing, utility entrances, expansion joints, and where two slabs will join
• Horizontal barriers are made by applying 4 liters (one gallon) of termiticide per 3 square meters, usually accomplished by applying a coarse spray at low pressure
• Slab treatment involves drilling through the slab floor and injecting termiticides into the soil at regular intervals