contracting of a concrete prior to its final set caused by hydration of the cement paste.

is an important phenomenon in young concrete. At low water/cement ratios, less than about 0.42, all the water is rapidly drawn into the hydration process and the demand for more water creates very fine capillaries

occurs when the concrete is exposed to air containing carbon dioxide, When the hardened concrete is exposed to this type of air, the weight increases, and the concrete undergoes irreversible carbonation shrinkage.

caused by vapor migrating through the slab bringing soluble salts to the surface of the concrete.

are hollow spaces and cavities left in concrete mass on surface or inside the concrete mass where concrete could not reach.

occurs when water in moist concrete freezes it produces pressure in the pores of the concrete; if the pressure developed exceeds the tensile strength of the concrete, the cavity will dilate and rupture

occurs due to drying shrinkage or carbonation or due to differential shrinkage between the surface of the concrete and the main body of the concrete

is local flaking or peeling of a finished surface of hardened concrete as a result of exposure to cycles of freezing and thawing

Powdering at the surface of a concrete slab

Identify the hardened concrete defect

Identify the hardened concrete defect

Identify the hardened concrete defect

Identify the hardened concrete defect

Identify the hardened concrete defect

Identify the hardened concrete defect

It is the process of removing entrapped air from freshly placed concrete

repeated insertion and withdrawal of a rod

repeated insertion and withdrawal of a flat spade-like tool

In the case of high-strength concrete, the water-cement ratio is too low and concrete is too stiff to compact by hand. To compact such types of concrete, mechanically operated vibratory equipment must be used.

rocks that are formed by the crystallization of molten magma, as granite

rocks that have undergone a change in structure, texture or composition due to the natural agencies as heat and pressure especially when the rock becomes harder and more crystalline, as marble & quartzite and slate

Marble is a non-foliated metamorphic rock that forms through the metamorphism of what?

formed when quartz-rich sandstone or chert has been exposed to high temperatures and pressures. Such conditions fuse the quartz grains together forming dense, hard, equigranular rock

metamorphosis of clays and shales deposited in layers. May be separated into thin, tough sheets called slates. Colors are black green red, grey or purple.

rocks formed by the deposition of sediment by glacial action, as limestone and sandstone.

sedimentary rocks with no cleavage lines, low absorption, smooth, uniform in structure & composition. High compressive & tensile strength.

class of rock of cemented silica grains with texture ranging from very fine to very coarse. Colors vary from buff, red and light brown. Porous whereas 30% of volume composed of pores.

Is a form of limestone deposited by mineral spring especially hot spring; often has a fibrous or concentric appearance and exists in white, tan, cream-colored, and even rusty varieties.

Which of the following is NOT true about Polymers

Also called India rubber or caoutlchouc

man-masde rubber which is produced in manufacturing plants by synthesizing it from petroleum and other minerals.

a family of synthetic rubber that are produced by polymerization of chloroprene

polymer formed from the polymerization of the monomer.

a general-purpose synthetic rubber, produced from a copolymer of styrene and butadiene

is a polymer that displays elastic properties

is a "solid or highly viscous substance" of plant or synthetic origin that is typically convertible into polymers