material for civil engineering
DESCRIPTION
Material for Civil Engineering. aggregates. Definition. Materials (for construction) Inert material which, when bound together into a conglomerated mass by a matrix, form: - concrete, -mastic mortar, -plaster . - PowerPoint PPT PresentationTRANSCRIPT
hra 3
DefinitionMaterials (for construction) Inert material which, when bound together into a
conglomerated mass by a matrix, form: -concrete, -mastic mortar, -plaster.
An aggregation of sand, gravel, crushed stone, slag or other material composition used in combination with a binding medium to form: -bituminous and Portland cement, -concrete, -macadam, -mastic, -mortar cement, -plaster, or alone as: -railroad ballast, -filter beds, and -various manufacturing processes such as fluxing
hra 5
Natural Aggregates Taken from natural deposits without
change in their nature during production, with the exception of crushing, sizing, grading or washing
Includes: pumice, shells, iron ore, lime rock
hra 6
Manufactured Aggregates Aggregates produced as a direct
product, rather than as a by-product of a manufacturing process
Includes: Blast furnace slag Clay Shale; Light weight aggregates
hra 7
Synthetic – Artificial Aggregates By-product of an industrial process
Product of process developed to manufactured aggregate with special properties
Reclaimed or waste construction materials
hra 8
Classification based on Size FINE Aggregate passing 9.5mm (3/8”) sieve, passing sieve no 4 (4.75mm)
and predominantly retained on 75u (no 200) sieve Aggregate passing no 4 and retained on the no 200 (75um) sieve
COARSE Aggregate predominantly retained on the no 4 sieve (for Portland
Cement Concrete)
The no 8 or no 10 sieve (for bituminous concrete)
hra 9
Composition & Structures Natural Aggregates
Consist of naturally occurring material of mineral composition
Derived from rocks with single mineral or several different mineral
hra 11
Composition & Structures IGNEOUS ROCK
COOL MELTING FORMED (ABOVE OR BELOW THE EARTH’S SURFACE)
CONSISTS OF CRYSTAL OR MINERALS IN A CRYSTALLINE (OR GLOSSY) MATRIX
SIZE IS A FUNCTION OF COOLING RATE
hra 12
Composition & Structures SEDIMENTARY ROCK
FORMED BY THE CONSOLIDATION OF DEPOSITS, - WEATHERING PRODUCTS AND EROSION OF ROCKS (EARTH SURFACE)
LESS MECHANICAL COMPACTIONS
hra 13
Composition & Structures METAMORPHIC ROCK
FORMED BY THE APPLICATION OF INTENSE HEAT AND PRESSURE TO SEDIMENTARY ROCKS
LESS POROUS, STRONG MATRIX (RECRYSTALLIZATION)
STRONGED AND LESS ANISOTROPIC COMPACTED TO SEDIMENTARY ROCKS
hra 14
ROCKS TYPE Specific Gravity
POROSITY (% - vol)
IGNEOUS BasaltGranite
2.6 – 3.02.6 – 3.0
50 – 200100 – 250
SEDIMENTARY ShaleLimestoneSandstone
2.0 – 2.72.3 – 2.82.2 – 2.7
10 – 100 35 – 250 20 – 175
METAMORPHIC StateMarbleQuartzite
2.6 – 2.92.6 – 2.82.6 – 2.7
100 – 200100 – 250100 - 300
hra 15
Principles and Procedures The use and process:
QUALITY : high (estimate) COST : low (estimate)
The procedures: Excavation Transportation Washing Crushing Sizing
hra 16
proceduresProcessing plant
Site
Transportation (truck, rail, conveyor belt)Washing : before and/or after
Excavator: diggingRemoval of organic material (silt; clay; leaves; mud)Method: blasting; dragging; pumping
hra 17
Sizing and screening
1. Sizing: by crusher2. Proper and desirable size3. Crusher type: size of designed
aggregate
Sieve : vibratory screenSet of sieves with designated diameter
hra 19
Sieve analysis
h
D
X gram
(X- z) gram
Retained = coarser
X’ gram coarser
X” gram finer
X”‘ gram finer
hra 20
Grain distribution
10 1 0.1 0.01 0.0.010
20
60
80
100%
by
weig
ht fi
ner
Diameter, log, mm
40