Concrete Flexural Strength Testing Quiz

The activity involves various tests on Portland cement
The tests include fineness, time of setting (Gillmore and Vicat needles), normal consistency, and compressive strength of mortar
The specifications used are primarily ASTM C184, C191, C266, C187, and C109

Fineness of hydraulic cement is a property indicating particle size and surface area.
Fineness affects hydration rate and strength
Bleeding can be reduced through higher fineness
ASTM C184 standard covers fineness of hydraulic cement.

ASTM C266 is the standard method for determining hydraulic cement's setting time using the Gillmore needle.
It covers the initial and final setting times
The Gillmore needle measures time till set by its change in consistency and position.

ASTM C187 standard covers the determination of the normal consistency of hydraulic cement.
The normal consistency varies between 25-35% for ordinary Portland cement.
Water is added in this specified percentage to achieve the standard consistency of cement paste.

ASTM C109 determines compressive strength of hydraulic cement mortars using 2 inch or 50-mm cube specimens.
A universal testing machine (UTM) applies load for determining strength.
Load is applied to specimens and their strength recorded.
The load-applied is up to 400 lbs/s [900 to 1800 N/s].

ASTM C143 provides standard test method for slump of hydraulic-cement concrete.
The slump test measures consistency of fresh concrete before setting
The consistency of freshly-made concrete is checked, assessing ease of flow and workability.
The test uses a slump cone to determine the slump.

ASTM C31 is the standard practice for making and curing concrete test specimens in the field.
Standardized requirements are defined for making and curing specimens.
Different specimen types such as concrete cylinders and beams are prepared and cured.

ASTM C39 is the standard test method for compressive strength of cylindrical concrete specimens.
Various factors, such as load, are considered in determining concrete compressive strength.

ASTM C78 standard test method is used to determine the flexural strength of concrete by using a simple beam with third-point loading.
Different failure types are identified, such as compression, shear and splitting during static bending.

Steel is a major component in many construction materials, including buildings, bridges, and automobiles.
Steel is an alloy of iron and carbon (carbon content of 2%, above 1% it's cast iron).
Key properties include strength, ductility, malleability, weldability, and durability.

Carbon Steel is the most common type, containing a tiny amount of carbon.
Alloy Steel contains one or more additional elements beyond iron and carbon (e.g., chromium, copper).
Tool Steel gives extra hardness and resistance to wear, often tempered.
Stainless Steel has high proportions of chromium and nickel, resistant to corrosion.

Deformed bars have surface projections for better bond strength with concrete.
CTD (Cold Twists Deformed) bars have higher construction costs compared to deformed bars.
However, by twisting, the yield strength of CTD bars achieves the level of Grade 60, but the ultimate strength remains at Grade 40 strength.
These bars save costs when used in less critical construction areas.

Nominal dimensions (area, weight, diameter) are specified for standard steel bars according to ASTM standards.
Different bar sizes (designated by numbers) have varying nominal dimensions.
Units include inches and millimeters.

A tension test measures the tensile strength of steel reinforcement bars.
The process involves applying increasing tension and measuring the stress-strain curve up to fracture.

Concrete masonry units (CMUs) are large rectangular blocks of varying types, used in construction.
CMUs include load-bearing, non-load-bearing, and different types like building tiles and bricks
Key materials are concrete (cement, sand, gravel, stone powder).
Types of CHBs include hollow load bearing, solid load bearing, hollow non-load-bearing, concrete building tile, and concrete brick.
Common ASTM tests for CHB include C90, C476, C55, C1634, C129, C139, and C744.
Additional classifications involve weight, fire rating, compressive strength & drying time.

Wood is a porous and fibrous structural material found in tree and other woody plants used for thousands of years.
Natural wood is categorized as hardwood and softwood.
Engineered wood includes plywood, particle boards, and others.

Tensile strength is an important property of wood, relevant in tension along the grain, but challenging to test.
Compressive strength along the grain is pertinent for structural applications (pillars).
Shear strength is a key property of beams and slabs.
Bending strength refers to the strength of wood as a beam.
Torsion strength is determined by stressing the specimen to failure.
Hardness is essential in paving blocks or bearings, and impacts performance of similar uses.
Stiffness measures wood deflection under load.

Sapwood (younger, softer part of the wood), Xylem (woody tissue that provides support and conducts water/minerals).
Inner bark (layer that carries food from leaves), Phloem (part of bark carrying food to growing parts of the tree).
Annual rings (concentric layers that grow during one year).
Bark (Tough external covering of the woody stem, branch, or root).
Pith (inner central portion of the tree).
Heartwood (older, harder, inactive core of the tree).

Wood is categorized into natural and engineered wood.
Natural wood further categorized into hardwoods and softwoods.
Hardwoods are from dicots, usually broadleaf trees often evergreen in tropic & subtropics, and less hard compared to softwoods.

ASTM D4761 is a standard method for mechanical properties of lumber and wood-based structural materials.
ASTM D198 provides standardized test methods for static tests of lumber.
ASTM D143 covers methods for small clear specimens of wood in static bending /compression.
ASTM D-5456 is a method for determining compressive strength of wood.