MATERIALS ENGINEER (DAY 2 INFO)

what is item 200?

Aggregate Sub-Base Course

What is sub-base course?

is an integral layer (crucial layer) in construction roads, airfields, other pavement structures.

Materials used for sub-base course?

1. Granular

2. Recycled

3. Stabilized

a material that is Gravel, crushed stone, other aggregate materials

Granular Material

a material that is recycled concrete, asphalt, other construction material

Recycled Materials

a material that is treated with binders like cement, lime, asphalt to improve their load bearing capacity and durability

Stabilized Materials

thickness of sub-grade

150mm - 300mm

thickness of sub-base

100-300mm

thickness of base course

100mm-300mm

thickness of Binder course

(50mm-100mm)

a coat that is between base and binder course

prime coat

a coat that is between binder and surface course

tack coat

thickness of surface course

25 - 50mm

a coat used for surface course

seal coat.

what is item 201

aggregate base course

a layer of material in construction of a road. primary function is to provide stable base for the pavement, facilitate drainage and distribute loads

Aggregate Base Course

composition of base course

mixture of crushed stone, gravel and sand

Type of aggregate base coure

Unbound ; stabilized

Made of granular materials without any binding agents

unbound

includes binding agents like cement or asphalt to improve strength and stability

stabilized

Refers to process of compacting and stabilizing the material

Damping

aggregate base course material is evenly distributed across the road surface

spreading

proper curing ensures material gains strength overtime

curing

additives or stabilizer are mixed with aggregate

mixing

the surface is level to achieve uniform thickness

Leveling

it ensures proper slope and drainage

Grading

This is the crucial damping process. It is used to compress the aggregate, reducing voids and increasing density

Compaction

Quality control involves measuring the compacted density using _____

FDT Method (Field Density Test)

One of the most common methods that are used for field density test in highway construction

Sand Cone Method

Calculation for FDT

V hole = M_sand / Density of used sand

Wet Density = M_wet soil / V_hole

Dry Density =( (Wet Density x 100%) / Moisture Content ) + 100

Degree of COmpaction = (Dry Density x 100%) / Max Dry Density

What is Item 202

Crushed Aggregate Base Course

type of recycled concrete that is produced by crushing concrete that has been removed from old buildings, roads, other construction projects

Crushed Aggregate

What is item 203

Lime Stabilized road mix base course

type of base course in road construction where lime is used to improve engineering properties of base material

A lime - stabilized road mix base course

Hydrated lime shall be uniformly spread at specified percent using the _________

Dry or slurry (wet) methods

A typical slurry ratio is ______

1-ton lime to 2 cubic meter (1:2)

trial section shall be constructed ________ before actual base construction

atleast 2 weeks

if excavated materials are wasted, the volume involved shall be reported so that quality control requirements maybe adjusted accordingly. Submit project engineer _________

Certificate of waste

what is item 204

Portland cement stabilized road mix base course

Type of base layer used in road construction. This technique involves mixing portland cement with the existing or imported aggregate base materials to enhance their strength and durability

Portland Cement Stabilized Road Mix Base Course

For Item 204

Proportioning:

the amount of cement added to soil aggregate is from ________ of dry soil. Exact percentage shall be fixed by the Engineer based on preliminary tests and trial mixes.

6 -10 mass percent

What is item 205

Asphalt Stabilized Road Mix Base Course

Asphalt stabilized road mix base course which is also known as______

Asphalt - Treated Base

Construction technique where asphalt binder is mixed with aggregate to create a stable and durable base layer for roadways

Asphalt Stabilized Road Mix Base Course

For Item 205

Proportioning:

the amount of asphaltic material to be added to the soil aggregate shall be from _________ of the dry soil aggregate

4 -7 mass percent

What is item 206

Chemically Stabilized Road Mix Sub Base or Base Courses

Involve the use of chemical additives to improve the engineering properties of soil or aggregate materials used in the construction of road foundations.

Chemically Stabilized Road Mix Sub Base/Base Course

For Item 206:

Important Points:

Consist of __________ to improve the strength and other properties of ordinary soil for use as sub-base/surfacing materials

Application of polymer - based chemical soil additive

Polymer - based chemical soil additive shall be ________

less than 2% by weight of soil

the rate of dilution in each layer shall be __________ or one - part polymer - based chemical soil additive 5 to 9 parts of water

1:5 to 1:9

what is item 207

Portland Cement Treated Plant Mix Base Course

For item 207

Important notes:

The salvaged or new soil aggregate shall be pulverized until _________ of all material other than stone or gravel will pass a 4.75mm or sieve No.4

Atleast 80% mass percent

For item 207

Important notes:

The completed cement treated base shall be cured with a _______

Bituminous Curing Seal

For item 207

Important notes:

The rate of application of curing seal shall be between __________ and maitained ___________

0.5 to 1.0 L/m² ; atleast 5 days

Any material retained on a __________ and other unsuitable material shall be removed

50 mm sieve (2”)

What is item 208

Aggregate Stockpile

is a large, organized heap of aggregate stored for use in construction projects.

Aggregate Stockpile

Item 200: Aggregate Sub base course

Test Requirements

For every 300m³:

1G

1P (LL, PL, PI)

For every 1500m³

1C

For every 2500 m³

1-CBR

For every layer of 200mm

Atleast 1 group of 3 in-situ density tests for each 500m²

Item 201: Aggregate base course

Test Requirements

For every 300m³:

1G

1P (LL, PL, PI)

For every 1500m³

1C

1 Q (Grading, Plasticity, and Abrasion)

For every 2500 m³

1-CBR

For every layer of 200mm

Atleast 1 group of 3 in-situ density tests for each 500m²

Item 202: Crushed Aggregate base course

Test Requirements

For every 1500m³:

1F (Fractured Face)

Item 203: Lime Stabilized Road Mix Base Course

Test Requirements

Soil Aggregate For every 300m³

1G

1P (LL, PL, PI)

For every 1500 m³

1Q

Mix of every 300m³

1C (laboratory Compaction Test)

1-UC (Unconfined Compression Test)

1-CBR

Compacted Base Course. For every layer of 200mm compacted depth

1D
1T

Hydrated lime. For every 100

1Q

Item 204: Portland Cement Stabilized Road Mix Base Course

Test Requirements

Soil aggregate - Same as 203

Cement:

1Q - for every 2000 bags

Water

1Q - Project Engineer’s Certificate

Mix. For every 300m³

1C

1 - UC

1 CBR

Compacted Base Course

1D - FDT for every 150m

1T - thickness determination for every 150mm

Item 205: Asphalt Stabilized Road Mix Base Course

Proportioning of Mixture

the amount of asphaltic material to be added to the soil-aggregate shall be from ___________ of the dry soil aggregate

4 to 7 mass percent

What is item 205

Asphalt Stabilized Road Mix Base Course

what is item 206

Chemically stabilized road mix sub base/base course

involve the use of chemical additives to improve the engineering properties of soil or aggregate materials used in construction of road foundations

Chemically Stabilized Road Mix Sub Base or Base Course

item 206: Chemically stabilized road mix sub base/base course

Important notes

Consists of __________________ to improve the strength and other properties of ordinary soil for use as subbase surfacing materials

Application of polymer - based chemical soil additive

item 206: Chemically stabilized road mix sub base/base course

Important notes

Polymer-based chemical soil additive shall be ____________

less than 2 % by weight of soil

item 206: Chemically stabilized road mix sub base/base course

Important notes

The rate of dilution in each layer shall be _______or one part polymer-based chemical soil additive 5 to 9 parts of water.

1:5 to 1:9

item 206: Chemically stabilized road mix sub base/base course

Unit of measurement is

LITER

is a versatile, durable, composite material made by mixing a variety of mineral fillers with synthetic or natural resin binding agent

Polymer Concrete

what is item 207

Portland Cement Treated Plant Mix Base Course

item 207: Portland Cement Treated Plant Mix Base Course

important notes:

The salvaged or new soil aggregate shall be pulverized until ___________ of all material other than stone or gravel will pass a 4.75 mm or sieve No. 4

At least 80% mass percent

item 207: Portland Cement Treated Plant Mix Base Course

important notes:

The completed cement treated base shall be cured with a

Bituminous Curing Seal

item 207: Portland Cement Treated Plant Mix Base Course

important notes:

The rate of application of curing seal shall be between ________ and maintained at least ______

0.5 to 1 liter/m² ; 5 days

item 207: Portland Cement Treated Plant Mix Base Course

important notes:

Any material retained on a ________ and other unsuitable material shall be removed

50mm sieve (2”)

what is item 208

Aggregate Stockpile

is a large, organized heap of aggregate stored for use in construction projects

Aggregate Stockpile