for Road con and maintainance

1. Weekly Report of AACRA Practice and site visit
Date Activities Group Trainer Remarks
May 14,2014  Observation of AACRA Road material testing rooms.
a. Soil testing room – 1
b. Asphalt testing room - 2
c. Concrete testing room – 3
 Explanation layer of road construction
 The equipment of the road material testing there how the
Operate the equipment and procedure.
2 Ato Mamo
(Lab assistant
of the AACRA)
May 16, 2014  Legetafo site visit
Excavation equipment
a. Excavator b. Dump truck c. Leveling instrument
 Types of excavation
a. Common excavation b. Rock excavation c. Soft soil excavation
d. Bulk excavation
 Step in road work construction
a. Preminary surveying
b. Design
c. Site work
d. Clearing and grubbing
e. Layout/setout stakeout the right at way limit
f. Excavation
The soil is black cotton soil and excavated at the depth of
1.6m and the length is about 60m long
There is rock found during excavation these time the
contractor asked a request to the owner for the approval of
rock excavation
2 Ato Habtamu
( Chief survey
of the Legetafo
site)

2. May 21, 2014  Site visit of around Balderas site
i. The span of the road 20m and the length around 1km long.
ii. Constructing of retaining wall
iii. Segregating of water
iv. Base course preparation by mixing of 00, 01, 02 aggregate
size and the thickness is 25mm
v. The moisture content of the base course
2 Engr. Tilahun

3. I. Trainees Name sign
1. Aregahegn Tilahun
2. Ashebir Mathewos
3. Asmera Taye
4. Awol Shengo
5. Ayele Mamo
6. Belaynesh Mekonnen
7. Belete Aweke
8. Bikila Asefa
9. Dawit Keba
II. Checked By
Ato Mamo
(AACRA Lab Testing Assistant Representative)
Ato Habtamu
( Chief survey of the Legetafo site)
Engr. Tilaun
(Contractor of the Balderas site)
Engr. Ramil D.Henares
(Instructor of Tunnels)
Ato Tsegaye W/Tsedik
(Dept. Head FTTI)

4. a. Soil testing room – 1
According to the soil foundation of the road classified in to three types.
(i) Sand. Sand is a disintegrated rock whose particles vary in sizes from 6
mm to o.o5 mm. Sand is further classified as coarse or fine sand depending
upon the grain size. The sand is a granular and non-cohesive material.
(ii) Silt. This is very fine sand and is a granular material having particles of
size smaller than 0.05 mm. It is a no cohesive material and has little or no
strength, and compacts very poorly.
(iii) Clay. Clay is a cohesive material having particles of microscopic size. Due
to cohesiveness these have high strength when dry. These changes in
volume considerably with the variation of moisture contents. The strength
of these soils can be increased by blending with granular soils.
b. Asphalt testing room – 2
Asphalt is a dark brown to black material cementations material in which the
predominating constituents are bitumen that occur in nature or are obtained in
petroleum processing. Asphalt is present in varying proportions in most crude
petroleum.
The crude petroleum is refined to separate the various fractions and recover
asphalt. Similar process is occurring in nature have formed natural deposit of
asphalt, some practically free from extraneous matter and some in which the asphalt
has become mixed with variable quantities of mineral matter, water, and other
substances. Natural deposits in which asphalt occurs within a porous rock structure
are known as rock asphalts.
Properties:
Asphalt is strong cement, adhesive, highly waterproof, and durable. It is a plastic
substance that imparts controllable flexibility to mixtures of mineral aggregates
with which it is usually combined. It is moreover highly resistant to the action of
most acids, alkalies and salts. Although a solid or semisolid at ordinary atmospheric
temperatures, asphalt may be liquefied by the application of heat, or by dissolving it
in petroleum solvents of varying volatility, or by emulsification. Almost all asphalt
used in the world is refined from petroleum. Such asphalt is produced in a variety of
types and grades ranging from hard brittle solids to almost water thin liquids. The
semisolid form, known as asphalt cement, is the basic material. Cutting back or
blending asphalts with petroleum distillates or by emulsifying them with water
generally prepares liquid asphalt products.
Recommendation: As the climatic condition of the city of Addis Ababa is cold to
moderately cold for whole of the year, this manual therefore recommends the use of
Asphalt Grade 85 – 100 for the heavily traffic roads.

5. Terms Related to Asphalt and its uses:
 Asphalt The term “asphalt” is usually interchangeable for bitumen. A dark brown to
black cementicious material; solid, semisolid, or liquid in consistency; in which the
predominating constituents are bitumen which occurs in nature as such or which are
obtained as residue in refining petroleum”. (ASTM Designation D8)
 Asphalt, Catalytically Blown Air-blown asphalt produced by using a catalyst during
blowing Process.
 Asphalt Cement Asphalt, which is refined to meet specifications, for paving or, other
special purposes. Its Penetration is usually ranges from 40 to 300. The term is often
abbreviated A.C.
 Asphalt Joint Filler An asphaltic product used for filling cracks and joints in
pavement and other structures.
 Asphalt, Liquid an asphaltic material having a soft or fluid consistency that is beyond
the range of measurement by the normal penetration test, the limit of which is 300
maximum.
 Asphalt Mineral filler Asphalt containing finely divided mineral matter passing
No.200 sieve.
 Bitumen – A mixture of hydrocarbons of natural or pyrogenous origin, or a
combination of both; frequently accompanied by non-metallic derivatives which may
be gaseous, liquid, semi-solid, or solid; and which are completely soluble in carbon
disulfide or carbon tetra-chloride.
 Asphalt Base Course A foundation course consisting of mineral aggregate, bound
together with asphaltic material.
 Asphalt Concrete High quality, thoroughly controlled hot mixture of asphalt cement
and well-graded, high quality aggregate, thoroughly compacted into a uniform dense,
mass.
 Asphalt Pavements :- Pavements consisting of a surface course of 25 mm or more of
mineral aggregate coated and cemented together with asphalt cement on supporting
courses such as asphalt bases; crushed stone, slag or gravel; or on Portland cement
concrete, brick or block pavement.
 Asphalt Prime coat Application of low viscosity liquid asphalt to an absorbent
surface. It is used to prepare an untreated base for an asphalt surface. The prime
penetrates into the base and plugs the voids, hardens the top and helps bind it to the
overlying asphalt course. It also reduces the necessity of maintaining an untreated base
course prior to placing the asphalt pavement.

6. c. Concrete testing room – 3
Properties of Portland cement:
 Most specifications for Portland cement place limits on its chemical composition and
certain physical properties. An understanding of the significance of some of these
properties is helpful in interpreting results of cement tests. In general, tests of the physical
properties of the cement should be used merely to evaluate the properties of the cement
rather than the concrete. 8-2.1
 Fineness: Fineness of cement affects the rate of hydration. Greater cement fineness
increases the rate at which cement hydrates and thus accelerates strength development.
The effects of greater fineness on strength are manifested principally during the first
seven days. 8-2.2
 Soundness: Soundness refers to the ability of a hardened paste to retain its volume after
setting. Lack of soundness or delayed destructive expansion is caused by excessive
amounts of hard-burned free lime or magnesia. Most specifications for Portland cement
limit the magnesia content and the autoclave expansion. Since the adoption of the
autoclave expansion test by ASTM in 1943, there have been exceedingly few cases of
abnormal expansion attributed to unsound cement.
 Consistency: Consistency refers to the relative mobility of a fresh mixture, or its ability
to flow. During cement testing, pastes are mixed to normal consistency as defined by a
penetration of 10±1mm of the Vicat plunger, while mortars are mixed to obtain either a
fixed water-cement ratio or to yield a flow within a prescribed range. Both the normal
consistency method and the flow test are used to regulate water contents of pastes and
mortars; both allow comparing dissimilar ingredients with the same penetrability of flow.
During concrete testing, the consistency of concrete is measured by the slump test.
 Setting Time: To determine if a cement paste undergoes setting and hardening during
the first few hours, setting-time tests are performed using either the Vicat apparatus or a
Gillmore needle. Initial set of cement paste must not occur too early; final set must not
occur too late. The setting times indicate that the paste is or is not undergoing normal
hydration reactions. Setting times of concretes do not correlate directly with setting times
of pastes because of water loss to air or substrate and because of temperature differences.
 Compressive Strength: Compressive strength of Portland cement as specified by
ASTM C150 is that obtained from tests of standard 50mm mortar cubes. These cubes are
made and cured in a prescribed manner using standard sand. Compressive strength is
influenced by the cement type, or more accurately, the compound composition and
fineness of the cement. Typically, cement strengths exceed the ASTM minimum
requirements by significant but different amounts. When early strengths with blended
cements are important, concrete mixes should be proportioned for early age and not 28-
day strengths.

7. The road construction there is seven layers and testing
1. Sub-Grade:- (1) The top layer of specified thickness of embankment or excavated
areas on which the pavement structure including shoulders is constructed. (2) The top
of a roadbed upon which the pavement structure and shoulders are constructed. The
taking test as following
 Classification of soil
a. Silt b. sand c. clay
 PI; Plastic index = LL(liquid limit) – PL( Plastic limit)
 California Bearing Ratio (CBR):- (CBR) The ratio of the force required to
penetrate a soil mass with a circular piston of 50 mm diameter to the force
required to penetrate a mass of high quality crushed stone with the same
piston. The rate of penetration in both cases is 1.27 mm per minute
 Shrinkage test :- a type of test which is that putting a soil in tube like metal
put on the oven
 Proctor test
a. Compaction
b. Modify
c. Standard
d. Mechanical compaction
2. Capping:-
Under the capping there are three type of test
a. PI test
b. Proctor test
c. CBR test
3. Sub-Base:- The layer or layers of specified or selected material of designed thickness
placed on a sub-grade to support the base course
Under the sub base there are three type of test
a. PI test
b. Proctor test
c. Gradations test
4. Base Course:- The layer or layers of specified or selected material of designed
thickness placed on a sub base or sub grade to support a surface course
Under the base course there are three type of test
a. PI test
b. Proctor test
c. Gradations test or sieve analysis
d. Flakiness index
e. CBR test

8. f. LAA – Los anjles ape ration
5. Prime Coat:- The application of a low viscosity liquid bituminous material to an
absorbent surface, preparatory to any subsequent treatment, for the purpose of
hardening or toughening the surface and promoting adhesion between it and the
superimposed construction.
6. Base Asphalt:-One or more layers of a pavement structure designed to
accommodate the traffic load, the top layer of which resists skidding, traffic abrasion,
and the disintegrating effects of climate. The top layer is top layer is sometimes called
Wearing Course. The mixing size of the aggregate 00, 01, 02 and bitumen.
Under the base Asphalt there are three type of test
Bitumen test
a. Quality test
b. Safety test
c. Grade test
7. Surface Asphalt: - An application of bituminous material and cover aggregate the
mixing size of the aggregate 00, 01 and bitumen.
Under the surface Asphalt there are three type of test
Bitumen test
a. Quality test
b. Safety test
c. Grade test