Investigation of Date Palm Seed Ash (DPSA) as Pozzolana in Concrete

This research investigates the improvement of the mechanical and durability properties of concrete using Date Palm Seed Ash (DPSA) as partial replacement of cement. The DPSA used was obtained by controlled burning of date palm seed in a kiln at a maximum temperature of 630oc for eight hours and after cooling, it was sieved through 75um sieve and its oxide composition analysis was conducted using X-ray fluorescence (XRF) procedures. DoE method of mix design was used to produce concrete ingredients for grade 30N/mm2 giving a water-cement ratio of 0.53. The effect of fineness of DPSA on cement paste and concrete was investigated through consistency, setting time and compressive strength tests using 2.5% replacement of cement with DPSA and different fineness (600um, 300um, 150um and 75um) of DPSA. The effect of partial replacement of cement with DPSA on cement paste and concrete using 0%, 2.5%, 5%, 7.5%, 10%, 15% and 20% DPSA was also investigated through consistency and setting times tests, workability test, density test, compressive strength test (at 7, 21, 28 and 56 days curing age), pozzolanic activity index and water absorption test. The results showed that DPSA has high Silicon dioxide (45.50%), Aluminium oxide (20.75%) and Iron oxide (7.25%). The results also reviewed that the consistency and setting times of cement-DPSA paste decreased with increase in the fineness of DPSA; but increased with increase in the replacement of cement with DPSA. Whereas the workability of DPSA concrete decreased with increase in cement replacement, the density increased with increase in cement replacement. Results of compressive strength showed that the finer the DPSA, the higher the concrete strength; and that cement can be replaced with DPSA up to 10% as the compressive strength at 10% replacement is 31.5N/mm2 as against the 31N/mm2 of the normal concrete, at 56 days. The pozzolanic activity index result reviewed that DPSA concrete meets up the minimum requirement of 75% specified by ASTM C618. Also, the water absorption capacity of DPSA concrete at the highest replacement (20%) is 11% less than that at 0%.

TABLE OF CONTENTS

Title page ............................................................................................................................. i

Declaration .......................................................................................................................... ii

Certification ....................................................................................................................... iii

Approval ............................................................................................................................ iv

Acknowledgements ..............................................................................................................v

Dedication .......................................................................................................................... vi

Table of contents ............................................................................................................... vii

List of tables ....................................................................................................................... xi

List of figures .................................................................................................................... xii

List of abbreviations ........................................................................................................ xiii

Abstract ..............................................................................................................................xv 

CHAPTER ONE ................................................................................................................1

1.1 General introduction ......................................................................................................1

1.2 Statement of the research problem .................................................................................2

1.3 Justification of the research ...........................................................................................3

1.4 Aim and objectives of the research ................................................................................3

1.4.1 Aim .............................................................................................................................3

1.4.2 Objectives ...................................................................................................................3

1.5 Scope and Limitations of the study ................................................................................3

1.5.1 Scope ...........................................................................................................................3

1.5.2 Limitations ..................................................................................................................4

1.6 Significance of the research ...........................................................................................4

1.7 Contributions to knowledge ...........................................................................................4 

CHAPTER TWO ...............................................................................................................5

Literature review ..................................................................................................................5

2.1 Preamble ........................................................................................................................5

2.2 Normal concrete .............................................................................................................5

2.3 Constituent materials of concrete ...................................................................................6

2.3.1 Cement ........................................................................................................................6 

  viii 2.3.2 Aggregates ..................................................................................................................9

2.3.3 Water .........................................................................................................................10

2.3.4 Chemical admixtures ................................................................................................10

2.4 Pozzolanic materials ....................................................................................................10

2.4.1 Types of pozzolanic materials ..................................................................................11

Natural pozzolanic materials ..............................................................................................11

Mineral slag .......................................................................................................................11

Ashes of organic origin and waste materials .....................................................................11

Certain natural sands and crushed rock products ...............................................................12

2.4.2 Types of pozzolanic cement ......................................................................................12

2.5 Date palm seed .............................................................................................................12

2.5.1 Origin of date palm seed ...........................................................................................12

2.5.2 Development of date palm fruits ...............................................................................13

2.5.3 Production of date palm seed ....................................................................................13

2.5.4 Use of date palm seed as aggregate in concrete ........................................................14 

CHAPTER THREE .........................................................................................................16

Research methodology .......................................................................................................16

3.1 Preamble ......................................................................................................................16

3.2 Materials ......................................................................................................................16

3.2.1 The raw date palm seed .............................................................................................16

3.2.2 The date palm seed ash .............................................................................................16

3.2.3 Cement ......................................................................................................................17

3.2.4 Fine and coarse aggregates .......................................................................................17

3.2.5 Water .........................................................................................................................17

3.3 Physical and chemical properties of concrete materials ..............................................17

3.3.1 Specific gravity of concrete materials .......................................................................17

3.3.2 Sieve analysis test .....................................................................................................17

3.3.3 Oxide composition of cement and DPSA .................................................................18

3.4 Concrete mix design ....................................................................................................18

3.5 Effect of fineness of DPSA on cement paste and concrete ..........................................18

3.5.1 Consistency and Setting Time of Cement – DPSA ..................................................18

3.5.2 Compressive strength test .........................................................................................18

3.6 Effect of partial replacement of cement with DPSA on cement paste and concrete ...18 

  ix 3.6.1 Consistency and setting times of cement-DPSA ......................................................18

3.6.2 Batching concrete ......................................................................................................19

3.6.3 Workability test of DPSA concrete ...........................................................................19

3.6.4 Density of DPSA concrete ........................................................................................19

3.6.5 Compressive strength test .........................................................................................19

3.6.6 Pozzolanic activity index (PAI) test .........................................................................20

3.6.7 Water absorption test ................................................................................................20 

CHAPTER FOUR ............................................................................................................21

Results and discussion .......................................................................................................21

4.1 Results ..........................................................................................................................21

4.1.1 Physical and chemical properties of concrete materials ...........................................21

(a) Specific gravity of sand, granite, cement and DPSA ...................................................21

(b) Sieve analysis of sand and granite ................................................................................21

(c) Chemical composition of DPSA and ordinary Portland cement ..................................22

4.1.2 Effect of fineness of DPSA on cement paste and concrete .......................................23

(a) Consistency and setting times of cement-DPSA paste .................................................23

(b) Effect of fineness of DPSA on concrete strength .........................................................24

4.1.3 Effect of partial replacement of cement with DPSA on cement paste and concrete 24

(a) Consistency and setting times of cement-DPSA paste .................................................24

(b) Slump of DPSA concrete .............................................................................................25

(c) Density of DPSA concrete ............................................................................................25

(d) Compressive strength of DPSA concrete .....................................................................26

(e) Pozzolanic activity index (PAI) of DPSA concrete .....................................................27

(f) Water absorption of DPSA concrete .............................................................................28

4.2 Discussion of results ....................................................................................................28

4.2.1 Physical and chemical properties of concrete materials ...........................................28

(a) Specific gravity of sand, granite, cement and DPSA ...................................................28

(b) Sieve analysis of sand and granite ................................................................................28

(c) Chemical composition of DPSA ..................................................................................29

4.2.2 Effect of fineness of DPSA on cement paste and concrete .......................................29

(a) Consistency and setting times of cement-DPSA paste .................................................29

(b) Effect of fineness of DPSA on concrete strength .........................................................30

4.2.3 Effect of partial replacement of cement with DPSA on cement paste and concrete 31 

  x (a) Consistency and setting times of cement-DPSA paste .................................................31 (

b) Slump of DPSA concrete .............................................................................................32 (

c) Compressive strength of DPSA concrete .....................................................................32 (

d) Pozzolanic activity index (PAI) of DPSA concrete .....................................................33

(f) Water absorption of DPSA concrete .............................................................................34 

CHAPTER FIVE .............................................................................................................35

Conclusions and recommendations ....................................................................................35

5.1 Conclusions ..................................................................................................................35

5.2 Recommendations ........................................................................................................35

References ..........................................................................................................................36

Appendices .........................................................................................................................42