Time of setting of hydraulic cement by vicat needle experiment

Kuwait University

College of Engineering & Petroleum

Civil Engineering Department

Building Materials Lab

CE – 252

Report #1

Normal Consistency and Setting Time of Hydraulic Cement

Conducted on: February 2rd, 2020

By:

Batoul Sultan Sultan 2161115732

Rawan Adel Alrshedi 2171120992

Hadel Bader Almutairi 2171114584

February 2th, 2020

Wednesday Group

On my honor I pledge that this work of mine does not violate the University provisions on academic misconduct. By signing below, I certify that I understand the University Policies on academic misconduct is committed; all parties involved are in violation.

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Abstract

There was two experiments were conducted in order to determine the normal consistency of the hydraulic cement and the second one to determine the setting time of the hydraulic cement. In the first part of the experiment used the Vicat apparatus particularly its rod to establish if the cement past was of the normal consistency. One needed to check if after 30 second of the rod being released, did the rod setting to a point 100 (+or-1) mm below the original surface or no? After various attempts, it was concluded that by using 650gm of cement and 160gm of water, the rod penetration had a value of 9mm, which puts the hydraulic cement at normal consistency. The second part (Setting Time of Hydraulic Cement Paste) was also conducted by the used of the Vicat needle. In order to determine the initial setting time, one needed to observe when the needle penetrates 25mm into the paste. However, to determine the final setting time, one needed to observe when the needle does not evidently sink into the paste.

i

Table of Contents

Abstract ……………………………………………………………………………………………………………………. i

Table of Contents ………………………………………………………………………………………………………. ii

List of Figures and Tables ………………………………………………………………………………………….. iii

Nomenclature …………………………………………………………………………………………………………… 1

Introduction: …………………………………………………………………………………………………………….. 2

Objectives: ……………………………………………………………………………………………………………….. 3

Theoretical Background: ………………………………………………………………………………………….. 3

Experimental Details (set up and procedure):……………………………………………………………. 4

Results and Discussion: …………………………………………………………………………………………….. 6

Subtitle 1:………………………………………………………………………………………………………….….. 6

Subtitle 2:……………………………………………………………………………………………………………... 7

Conclusions :……………………………………………………………………………………………………………… 8

Acknowledgements :…………………………………………………………………………………………………. 9

References :………………………………………………………………………………………………………………. 9

Appendix :…………………………………………………………………………………………………………………. 10

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List of Figures and Tables

Figure 1: Vicat apparatus ……………………………………………………………………………………………….. 4

Figure2: Vicat penetration versus amount of water………………………………………………………… 7

Figure 3: Needle penetration versus time……….……………………………………………………………... 8

Table 1: Data for determining the Normal consistency of cement paste…………………….…… 6

Table 2: Setting time by Vicat Apparatus…………………………………………………………………………. 7

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Nomenclature

Milligrams = gm

Millimeter = mm

Minutes = min

Second = Sec

Percentage = %

Wight of mixing water = W

Wight of cement = C

1

Introduction

Cement is a water-based binder used to bind other building materials together. It is used in the production of mortar and concrete during the construction process. In the experiment (Normal consistency of Hydraulic Cement) it was used Portland cement, is a finely ground powder composed of mineral compounds that react with water, set and harden. Portland cement is a manufactured product and is composed of for four main components, which are: (Lime, Silica, Alumina, and Iron). Also there are five common types of Portland cement.
The normal consistency of hydraulic cement
Is by determining the amount of water required to prepare cement paste for Initial and final time of setting test. That mean when we change the amount of water will have different consistency for cement.
Normal Consistency:
is a standard measure of plasticity of a Cement Paste , which has a normal consistency when a Vicat plunger penetrates (10 ± 1mm) in time (30sec). Also the time factor must be taken into consideration, to have good result. In this experiment we follow the ASTM C150 Standard.
What is the consistency test? A consistent test is one for which the power of the test for a fixed untrue hypothesis increases to one as the number of data items increases
What is Vicat test?
Vicat softening temperature or Vicat hardness is the determination of the softening point for materials that have no definite melting point, such as plastics. It is taken as the temperature at which the specimen is penetrated to a depth of 1 mm by a flat-ended needle with a 1 mm2 circular or square cross-section
Setting time of hydraulic cement:
The second experiment was used to determine the time of setting of hydraulic cement, by using the vacant needle. Not to mention it distinguish the time of the cement paste if it remains plastic loge enough to allow normal placing of concrete without obstructing final procedure.
2

Objectives:

A. Normal consistency:

This method covers determination of the normal consistency of hydraulic cement, which is the amount of water, required in preparing a hydraulic cement paste for testing.

B. Setting time:

This method was used to determine the time of setting of hydraulic cement by means of the Vicat Needle. It also determines if a cement paste remains plastic long enough, to permit normal placing of concrete without hampering finishing operation. It also establishes whether the cement complies with the specification limits of the setting time.

Theoretical Background:

Portland cement is finely ground powder composed of mineral compound that react with water, set and harden. Portland cement is manufactured product and is composed of for four main components, which are Lime, Silica, Alumina and Iron. There are five common types of Portland cement. Normal consistency is the cement paste shall be of normal consistency when the rod settles to a point 10(+or-) mm below the original surface 30 second after being released. Vicat apparatus is a penetration instrument used to find out the setting time (initial and final) and normal consistency of the hydraulic cement. Initial setting time is the time at which the needle penetrates 25mm into the paste and it was measured from the instant of mixing cement with water. Final setting time is the time at which the needle does not visibly into the paste, and it was measured from the instant of mixing cement with water