What is the meaning of soundness of cement?

The soundness of cement refers to the stability of the volume change in the process of setting and hardening. If the volume change is unstable after setting and hardening, the concrete structures will crack, which can affect the quality of buildings or even cause serious accidents, known as poor dimensional stability.

What is meaning of soundness of cement Mcq?

D : Ability to retain volume after setting. Correct Answer : Ability to retain volume after setting.

What should be soundness of cement?

The difference between needle readings indicates the soundness of cement. The soundness limit must exceed 10 mm for ordinary, rapid hardening, and low heat Portland cement. If in case the c expansion is more than 10 mm as tested above, the cement is said to be unsound.

What is sound and unsound cement?

After the drying of cement mortar or concrete, it should not undergo any appreciable change in volume. If there is a change in the volume, it will cause the cement to expand or contract. Therefore, there are chances of development of cracks. Such cement is called unsound cement.

What is soundness of cement Quora?

Soundness of cement is the property of hardened cement paste undergoing large change in volume after setting without delayed destructive expansion. This destructive expansion is caused by excessive amounts of free lime or magnesia. This change in volume may cause crack and disintegration of concrete.

soundness of cement meaning | what is soundness and unsoundness in cement |

What is called factor soundness?

Soundness test determines the disintegration of aggregates due to weathering. This includes freezing, thawing, marine condition etc. However, the weak and porous aggregate shows a change in weight during this soundness test. Aggregates are the significant factor that contributes adequate strength to concrete.

What is the use of soundness test?

The soundness test determines an aggregate's resistance to disintegration by weathering and, in particular, freeze-thaw cycles. Aggregates that are durable (resistant to weathering) are less likely to degrade in the field and cause premature HMA pavement distress and potentially, failure.

What causes unsound concrete?

Unsoundness is caused by free lime and magnesia in the clinker in sufficient quantity so that, upon hydration, excessive expansion and damage to concrete can occur. The presence of such is detected by the autoclave expansion test ASTM C 151.

What is concrete workability?

Workability of Concrete is a broad and subjective term describing how easily freshly mixed concrete can be mixed, placed, consolidated, and finished with minimal loss of homogeneity.

What is meant by consistency of cement?

Standard Consistency of Cement

The standard consistency of a cement paste is defined as the percentage of water added In 300gm weights of cement which will permit a Vicat plunger having 50 mm length and 10 mm diameter to penetrate in cement paste to a depth of 33-35 mm from the top of the mold.

Why do we test soundness of cement?

Unsoundness of cement makes the work saggy and looks like below one. That's the reason why we are testing the soundness of cement before using. This test ensures that the cement will not go any subsequent expansions due to excess amount of lime present in it.

What is hydration of cement Mcq?

1. What is hydration of cement? Explanation: As water comes into contact with cement particles, hydration reactions immediately starts at the surface of the particles. Explanation: It is difficult thus the rate of hydration decreases with time & as result hydration may take several years.

What do you mean by bulking?

Bulking is the muscle-gaining phase. You're meant to intentionally consume more calories than your body needs for a set period — often 4–6 months. These extra calories provide your body with the necessary fuel to boost muscle size and strength while weight training ( 1 ).

What is maturity of concrete?

Concrete maturity indicates how far curing has progressed. Maturity is the relationship between concrete temperature, time, and strength gain. It is represented by an index value that can be measured in real time in the field.

What is creep of concrete?

Definition: time-dependent deformation due to sustained load.- ACI Concrete Terminology. Creep is indicated when strain in a solid increases with time while the stress producing the strain is kept constant.

What is true slump?

True slump refers to general drop of the concrete mass evenly all around without disintegration. Shear slump indicates that the concrete lacks cohesion. It may undergo segregation and bleeding and thus is undesirable for the durability of concrete.

What is Slump loss?

Fresh concrete is well known to lose its workability with time. This phenomenon is called 'slump loss'. To improve slump retention with PNS or PMS, of which the action is often limited in time, addition of set-retarding water reducers, typically lignosulfonates, was found to be quite adequate.

What is curling of concrete?

WHAT is Curling? Curling is the distortion of a slab into a curved shape by upward or downward bending of the edges. The occurrence is primarily due to differences in moisture and/or temperature between the top and bottom surfaces of the concrete slab.

What is concrete Honeycombing?

This bumpy condition is often referred to as concrete honeycombing and causes broken bits of rock and stone on the edges of a concrete slab. While it's not always common, it's usually a result of voids in concrete due to the mortar not filling the spaces between coarse particles.

What is concrete pitting?

Concrete pitting is when the surface of a concrete structure begins to deteriorate. It's defined by a cluster of small holes that appear on the surface of the concrete. It's an extremely common problem in construction that occurs because of a problem with the way the concrete was produced.

Which instrument is used for soundness test?

The soundness of cement may be determined by two methods, namely the Le-Chatelier method and the autoclave method. The Le-Chatelier test detects unsoundness due to free Lime only.

What is expansion of cement?

Expanding cement is cement to which an expansive component is added. It is a true expanding cement, since the expansion occurs after the cement has set. As expansion occurs, the cement is restrained by the formation and by the casing so that expansion produces a self-stress in the cement.

What is flakiness and elongation?

Flakiness Index is the percentage by weight of particles in it, whose least dimension (i.e. thickness) is less than three-fifths of its mean dimension. Elongation Index is the percentage by weight of particles in it, whose largest dimension (i.e. length) is greater than one and four-fifths times its mean dimension.

What is compressive strength of cement?

Compressive strength is the capacity of material or structure to resist or withstand under compression. The Compressive strength of a material is determined by the ability of the material to resist failure in the form of cracks and fissure.