R1.3 RESP1.3 RESPONSE OF CIVIL ENGIONEEONSE OF CIVIL ENGINEERING PROJECT 1.3 RESPONSE OF CIVIL ENGINEERING PROJECT 1.3 RESPONSE OF CIVIL ENGINEERING PROJECT MASONRY BY : NOR AZAH BINTI AZIZ BY : NOR AZAH BINTI AZIZ

Identify and describe material response of modes primary failure due to: iii)Masonry a.Structure failure Sliding Diagonal Compression and Shear b.Performance failure Bedding joint Learning Outcomes

MASONRY

Masonry Masonry is the building of structures from individual units laid in and bound together by mortar. mortar Mortar - A mortar is made by mixing cement, water, air, and fine aggregates. The common materials of masonry construction are brick, stone, glass brick or concrete block

Masonry Masonry is generally a highly durable form of construction. Materials used, the quality of the mortar and workmanship, and the pattern in which the units are assembled can strongly affect the durability of the overall masonry construction. Masonry is commonly used for the walls of buildings, retaining walls and monuments.

(CBPI Masonry Teaching Package April 2000 [online]) Types of Masonry

i.Sliding ii.Diagonal iii.Compression iv.Shear Masonry Structure failure

Masonry boasts an impressive compressive strength (vertical loads) but is much lower in tensile strength (twisting or stretching. The tensile strength of masonry walls can be strengthened by thickening the wall, or by building masonry piers (vertical columns or ribs) at intervals. Masonry Structure failure

TENSILE STRESS: The type that tends to stretch a material, as though the forces were attempting to pull the molecules of the material apart. COMPRESSIVE STRESS: The type that tends to compress, or press together, or crush the molecules of the material. Masonry Structure Failure

SHEAR STRESS: The type that tends to slide or twist the molecules of the material apart. The numerical value of stress equals the amount of force divided by the cross section area of the member that is subject to force. Masonry Structure Failure

Failure Modes Shear Sliding shear Bending

Shear

In concrete or masonry structures, shear is resisted as diagonal tension.

Examples Wall Failure Shear Failure

Bending

The main forms of masonry failure in plane stress state. (a)Partition into columns. (b) Partition into layers of one or several masonry rows. (c) Splitting parallel to the external surfaces of the masonry. (d) Break along a bed joint. (e) Break along a tooting crack. (f) Vertical break through masonry elements. (g) Splitting along a stepped crack with shear along the bed. (h) Shear along the bed. (i) Splitting along an inclined crack.

(CBPI Masonry Teaching Package April 2000 [online]) Masonry Performance Failure The method of laying masonry units in a wall in a regular pattern for strength & generally in such a way that there are no continuous vertical joints (perpendiculars) in successive courses.  Bedding Joint

Normally structure failure for masonry structure occurs at bedding joint area. Bedding joint is the weakness point in masonry structure. Quality of the mortar and workmanship for bedding joint strongly affect the durability of the overall masonry construction. Masonry Performance Failure

R1.3 RESP1.3 RESPONSE OF CIVIL ENGIONEEONSE OF CIVIL ENGINEERING PROJECT 1.3 RESPONSE OF CIVIL ENGINEERING PROJECT 1.3 RESPONSE OF CIVIL ENGINEERING PROJECT TIMBER BY : NOR AZAH BINTI AZIZ BY : NOR AZAH BINTI AZIZ

Learning Outcomes Identify and describe material response of modes primary failure due to: iv)Timber a) Structure failure ● Compressive ● Tensile ● Shear b) Performance failure ● Decay/Rotting

TIMBER

One of the earliest materials to be used in building. Still continues to play a major part in general building, particularly in furniture industry. Building parts such as Window Frame, Door Frame, Trusses, Wall Panel, Flooring etc using timber still in used.

ADVANTAGE o simplicity in fabrication o lightness o reusability o insulation from heat. sound & electricity o aesthetically pleasing appearance o resistance to oxidation, acid attack & salt attack and salt water ADVANTAGE o simplicity in fabrication o lightness o reusability o insulation from heat. sound & electricity o aesthetically pleasing appearance o resistance to oxidation, acid attack & salt attack and salt water

DISADVANTAGE OF TIMBER The material may be very variable due to natural defect. Possible distortion when its moisture content changes. Fungal and insect attack Not good as fire resistant Easy to creep under load DISADVANTAGE OF TIMBER The material may be very variable due to natural defect. Possible distortion when its moisture content changes. Fungal and insect attack Not good as fire resistant Easy to creep under load

Timber Structure Failure i.Compressive ii.Tensile iii.Shear

Bending failure in compression Only likely for very high grade material Benign failure mode

Bending failure in tension Most likely failure mode Brittle Combination of tension and shear, although tension fracture is the initiating mode

Shear failures One of the very weak properties of wood Shrinkage cracks often occur at the ends of beams in the zone of maximum shear stress  Direct compression transfer of loads in the end zones reduces the total shear force to be carried. 45 o critical section This part of the load transferred in direct compression

Timber Performance Failure Whereas weathering is degradation of the wood surface, decay (also called rot) affects the full volume of wood. Decay is degradation caused by a variety of decay fungi that are capable of breaking down the structural components of wood for food.  Decay/Rotting

Timber Performance Failure The fungi tunnel throughout the full volume of the wood, degrading the polymers that form the wood cells through a complicated biochemical process. Since these polymers give wood its strength, considerable loss of strength occurs long before visible damage is apparent. Wood decay fungi must have adequate moisture to grow.  Decay/Rotting

Decay