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International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308

(Print), ISSN 0976 – 6316(Online) Volume 4, Issue 2, March - April (2013), © IAEME

295

EFFECT OF DYNAMIC LOAD: IMPACT OF MISSILE ON

MECHANICAL BEHAVIOR OF FERROCEMENT –

INFRASTRUCTURE APPLICATION

Mohammed Mansour Kadhum

PhD, Assistant Professor,

College of Engineering, Babylon University,

Iraq / Babylon / 40 Street

ABSTRACT

An investigation into the behavior of ferrocement barriers subjected to impact

load testing and missile impact is reported. This impact test was used to evaluate the

mechanical behavior of cement mortar panels reinforced with one or more of the following

reinforcement types: square steel chicken wire meshes, hexagonal steel chicken wire meshes,

steel fibers and polypropylene fibers randomly distributed in plane. One missile impact

velocity, size and weight was used to investigate the results of the influence of various

mechanical parameters on impact effects due to projectile impact.

This paper describes the first part of a study, which aims to apply of ferrocement

panel in road as a base course to treatments and investigate the wider issues with its

application to road pavements.

The test results showed that the depth of penetration of projectiles decreased

from 23mm for the plain cement mortar panel to 8.7mm for the ferrocement panels with

square steel wire mesh reinforced cement mortar Panels. Whereas, the cement mortar panels

which are reinforced with randomly distributed polypropylene fibers showed no enhancement

to impact resistance when measured by the depth of penetration caused by the projectiles.

Also, the drop load depth can be a reasonable indicator of cumulative damage in the case of

drop impact test

Keywords: Ferrocement; Missile impact; Projectiles; Depth of penetration; barriers

INTERNATIONAL JOURNAL OF CIVIL ENGINEERING AND

TECHNOLOGY (IJCIET)

ISSN 0976 – 6308 (Print)

ISSN 0976 – 6316(Online)

Volume 4, Issue 2, March - April (2013), pp. 295-305

© IAEME: www.iaeme.com/ijciet.asp

Journal Impact Factor (2013): 5.3277 (Calculated by GISI)

www.jifactor.com

IJCIET

© IAEME



296

1. INTRODUCTION

Fiber and mesh reinforced concrete was found to be adequate in sustaining

impact, blast, explosion and other forms of dynamic loads. Although, the toughening

mechanism was well understood in this composite material under statically applied loads,

unfortunately in case of impact and other dynamic loads, our understanding is inadequate

(Banthia et al., 1998).

Several studies such as (Mansur et al.,2000) on punching shear strength of

ferrocement have shown that due to its reinforcement characteristics it has an incredible

mechanical characteristics. However, they used a thin-walled composite comprising closely

spaced layers of fine wire mesh encapsulated in a cement mortar matrix. Generally, researchers (Ramakrishnan et al., 1980; Swamy and Jojagha 1982)

were used the drop weight test developed by (Schrader, 1981) and published by the (ACI

committee 544-1988) to measure the impact resistance of fiber reinforced cement composites.

The economical and environmental advantages of using reinforcement to

provide thinner road structures, longer life cycles and reduction in maintenance costs and of

course savings in natural resources due to prolonged service intervals.

On the other hand, the projectile impact feature could be more representative. In

general, the projectile impact mass leads to two types of responses which are: Firstly, the load

collision local effects such as surface indentation and local crushing suffered by the target or

penetration of the projectiles. Secondly, the overall dynamic responses of the target which

consist mainly of wave propagation and scabbing.

The depth of penetration is a function of the velocity and mass of the projectile

as well as the stiffness of the targets material. For concrete the latter parameter is normally

related to the compressive strength (Gao 2007).

In the present work, the first type of responses has been investigated which depends on the

following parameters:

- Projectile properties: weight, caliber, shape and strength.

- Target properties: strength, ductility and density.

- Striking velocity: impact velocity and angle of incidence.

2. EXPERIMENTAL PROGRAM

2.1 Testing procedure and instrumentation The ferrocement specimens which are subjected to test should be cast in rigid

dismountable moulds made of metal. The spacing of steel mesh wires and fiber reinforcement

in the moulds should correspond to the regular reinforcement ratios. The identical spacing

between particular layers of wire mesh in specimens and structure was attained. The details

of the test specimens are shown in Figure 1.



297

Figure 1. Dimension and detail of the specimen

The mould is supplied by separating combs that stabilize the horizontal position of wire

mesh and distance sheets that determine the stable vertical position of the wire mesh layers. The strips

of particular wire mesh layers passing through the separating combs and separated by distance sheets

are rigidly fixed in each opposite two ends of the mould.

In this experimental investigation, a spherical head of non-deformable type projectile

with a mass of about 0.2kg and diameter of 25mm was used. The small balls projectile were shoot

from a shooting gun as shown in Figure 2. The head and body of the projectiles were made from steel

and aluminum respectively. These projectiles were ejected by air pressure at velocity of about 218

m/sec; this speed is sufficient to model collision by an aircraft. Also, a high speed camera, which

capable of recording about 5350 frames per second was poisoned beside the specimen to record

collision behavior when the missile projectile approach to the tested panel specimen.

The panel specimen was suspended vertically in front of the gun by two steel slings to

allow free movement after impact. Also, the impact direction of the steel ball projectiles was mounted

normally to the ferrocement panel as can seen in Figure 2. After being impacted by the projectile

missiles, the panel specimens were examined visually. Various measurements, such as penetration

depth, dimension of damage area of both front and rear faces and weight of flying concrete were

determined. The shooting distance of the gun was kept at 5.0 meters away from the panel target.

Point of collision

gun

Steel and aluminum ball projectiles

Ferrocement panel barrier

Specimen Stopper

Figure 2. Dimension of the missile projectile an schematic impact test apparatus arrangement

B) Test Setup

A) Missile Projectile

Head

Body

45 20 10

45

400m

m

400m

m

Thickness of panel= 50mm

Steel wire mesh fixed

in place by rivets



298

For the ferrocement panel specimens which were subjected under impact load,

the conducted impact test was the drop-weight test. In this work, a testing apparatus

manufactured locally is presented. The details of this apparatus were presented by earlier

work of (Barr and Baghli 1989). The impact apparatus consists of three main components:

i. The supporting frame,

ii. The drop weight guide system, and

iii. The impact masses or strikers.

A special supporting frame was manufactured and used. This supporting frame

was made using four steel beams of the type W-shape (W4×13) welded and arranged to form a

square shape. Steel bars of (25mm) diameter welded on top faces of each four steel beams to

provide a simply support for the ferrocement panel specimen edge as shown in Figure 3.

The specimens simply supported and the impacting mass was dropped freely through the

guiding system at the center of the specimen by a line contact between the impacting mass

and the specimen surface. The front end of the impact masses has a rounded surface in order

to create a line contact between the impact mass and the test specimens. The numbers of

blows which cause ferrocement fracture were calculated as impact resistance. The energy

produced by each blow is given by the product of the drop height and weight of the striker,

and then the total impact energy is determined by multiplying the energy per blow by the

number of blows.

2.2 Casting and curing the panel specimens After the mould preparation, cement mortar mixture was mixed using a small

rotating mixer. Then the mixture is casted in the prepared mould in layers each of 5mm. For

the ferrocement panels a layer of chicken wire mesh was fixed in place each 10mm of depth;

i.e. 4 layers for each panel. While for the fiber reinforced cement mortar plates, the specified

Figure 3. Schematic diagram showing impact apparatus



299

quantity of (crimped steel or polypropylene) fibers was randomly dispersed in plane each

5mm depth layer.

The fresh panels with the mould were covered with polyethylene sheets

immediately after casting to prevent dryness and plastic shrinkage cracks. Two days later the

mould was dismantled carefully and the panels were moist cured by immersing in a water

curing basin for 28 days. After this period of curing the panels were taken off the curing

basin, dried for about two hours before conducting the experimental tests.

2.3 Materials Ordinary Portland cement and natural sand passing through sieve 2.38mm were

used in the ratio of (cement : fine aggregate was 1:1) by weight. The water-cement ratio used

kept was 0.5. To improve workability, a superplastisizers was added at 0.065% by weight of

cement. Galvanized welded wire meshes were used throughout the test program.

2.4 Types of ferrocement panel specimens The ferrocement panel specimens were reinforced with the following types of

reinforcement:

1- Steel chicken wire meshes.

2- Steel fibers.

3- Polypropylene fibers.

4- Steel chicken wire meshes and steel fibers.

5- Steel chicken wire meshes and polypropylene fibers.

In the present study, the impact resistance of these five types of ferrocement

panel specimens was determined. The panel designation, mix proportions and reinforcement

details are given in Table 1. The properties of crimped steel fibers and polypropylene fibers

which were used as reinforcing fibers are given in Table 2. Also, the properties of the square

steel wire meshes and hexagonal steel wire meshes which were used as reinforcing wire

meshes are given in Table 3.

Table 1. Specimens designation and reinforcement details.

Specimen

s Type of Reinforcement

Fibers

Volume

Fraction %

Steel Wire meshes

% by Volume

RP Plain cement mortar ---- ----

FS1 Steel fibers 0.9 -----

FS2 Steel fibers 0.8 -----

FP1 Polypropylene fibers 0.9 -----

FP2 Polypropylene fibers 0.8 ----

FM Square steel wire mesh ---- 0.9

FH Hexagonal steel wire mesh ---- 0.8

FMS Square steel wire mesh + steel fibers 0.45 0.45

FMP Square steel wire mesh + polypropylene

fibers 0.45 0.45

FHS Hexagonal steel wire mesh + steel fibers 0.4 0.4

FHP Hexagonal steel wire mesh + polypropylene

fibers 0.4 0.4



300

Table 2. Properties of the reinforcing fibers

Fiber Type Density

kg/m3

Tensile

Strength (MPa)

Equivalent Diameter

(mm)

Length

(mm) Aspect Ratio

Crimped steel 7700 1080 0.4 40 100

Polypropylene 925 330 0.42 50 119.05

Table 3. Properties of the steel chicken wire meshes.

2.5 Compressive strength test The specimens which will be tested finally for compressive strength were

obtained by cutting six cubes of dimensions 50mm × 50mm × 50mm from each plain mortar,

fiber reinforced mortar and ferrocement panel.

Practically, the best direction of cutting the cubes is obtained by putting the

panel in the same position at which it was cast with mortar; as the upper surface is weaker

than the molded surfaces. Such method of cutting ensures that the strength of concrete is

justifiable because there is no significant amount of splinters and fragmentation and hence the

quality of planes and dimensional tolerances are attained to be in the best manner.

3. TEST RESULTS AND DISCUSSION

3.1 General

All panels were conducted with identical projectile velocities of 218 m/sec. The

results of the projectile penetration test, the compressive strength, impact resistance test; and

density tests are given in Table 5. Additionally, Figure 4 and 5 demonstrate the values of

projectile penetration into each type of panel with the designated reinforcement.

From Figure 4 and 5, the effect of the type of reinforcement on the depth of

penetration can be clearly detected. However, it can be seen obviously from Figure 4 that the

ferrocement panel which was reinforced with square steel chicken wire mesh (FM) with

(0.9%) volume fraction of steel reinforcement has shown the lowest value of depth of

penetration (8.7mm). This proves that it has superior characteristic in impact resistance than

the other panels. Whereas, the panel which was reinforced with the polypropylene fiber (FP1)

has the highest value of depth of penetration (23.3mm), which means that it acquires the

lowest impact resistance compared with the other panels even the non reinforced one

(23.0mm). Also, it can be seen that the cement mortar panel which was reinforced with

(0.9%) volume fraction of crimped steel fibers randomly distributed in plane possessed a low

value of projectile penetration (9.0mm) which indicates remarkable impact resistance.

On the other hand, the ferrocement panel which was reinforced with (0.8%)

volume fraction of hexagonal steel chicken wire mesh (FH) has shown a low value of depth

of penetration (8.9mm). While, the panel which was reinforced with the polypropylene fiber

Wire Meshes

Wire

Diameter

(mm)

Density

kg /m3 Tensile Strength (MPa)

Weight per Unit

Area

kg /m2

Square Meshes 0.20 7720 980 0.2765

Hexagonal

Meshes 0.29 7680 938 0.2474



301

randomly distributed in plane (FP2) has a depth of penetration of (22.9mm). Actually it is

equal to that of the non reinforced panel as can be seen in Figure 5.

However, the preceded experimental results clearly indicate that the ferrocement

panels reinforced with steel wire meshes or the steel fibers are possess appreciable impact

resistance and can successfully used as barriers against impact loads.

Effect of volume fraction and different types of fibers (steel and polypropylene)

on the characteristics of impact test is presented in Figures 6 and 7. From the results, it is

clear that the impact resistance of the ferrocement was improved with higher ratio of volume

fraction and type of fiber. Also, it can be seen from these results that the energy input

required to initiate first crack and to produce failure in fiber reinforced panel specimens is

very much greater than that for plain cement mortar.

Table 5. Results of the conducted tests.

Specim

en

Failure Mode Weight

of

Flying

Concret

e (kg)

Density

kg/m3

Compress

ive

Strength

(MPa)

No. of

Blows

Total

Absorb

ed

Energy

(N.m)

Mean

Depth of

Penetrati

on (mm)

Perforati

on

Scabbin

g

at

First

Crac

k

at

Fail

ure

RP 2.60 2120.00 40.0 3 19 745.6 23.0

F S1 2.15 2160.00 46.4 6 77 3021.5 9.0

FS2 2.05 2159.50 45.0 5 68 2668.3 9.1

FP1 3.10 2104.24 37.0 4 23 902.5 23.3

FP2 2.92 2105.46 39.0 3 21 824.0 22.9

FM 1.95 2166.20 49.0 6 73 2864.5 8.7

FH 2.18 2165.06 47.0 5 71 2786.0 8.9

FMS 1.90 2165.70 48.0 9 93 3649.3 8.8

FMP 1.74 2134.50 40.4 5 52 2040.5 9.2

FHS 1.90 2160.03 46.2 8 86 3374.6 9.0

FHP 2.00 2132.46 40.2 5 48 1883.5 9.3

Figure 4. Effect type of fiber and square steel wire

mesh

reinforcement on depth of projectile penetration

Figure 5. Effect type of fiber and hexagonal steel

wire mesh

reinforcement on depth of projectile penetration

Specimens Designation

8

10

12

14

16

18

20

22

24

Dep

th o

f P

en

trati

on

(m

m)

FP1 RP FMP FS1 FMS FM

Specimens Designation

8

10

12

14

16

18

20

22

24

Dep

th o

f P

en

trati

on

(m

m)

RP FHP FS2 FHS FHFP2



302

In addition and depending on the obtained results of both projectile penetration depth

and the compressive strength of the panels, it was found that there is a negative relationship

between the mean depth of projectile penetration on one side and the compressive strength on

the other side as shown in Figure 8.

Furthermore, it was found that while the non reinforced (plain) cement mortar panel

possessed 23.0mm depth of projectile penetration with 40MPa compressive strength, the

ferrocement panel which was reinforced with square steel wire mesh possessed 8.7mm depth

of projectile penetration with 49MPa compressive strength. However, from the preceded

results it can be concluded that the inclusion of steel wire mesh reinforcement which is

decrease the depth of projectile penetration by about (37.8%) can correspondingly result an

increase in the compressive strength by about (22.5%).

Figure 8. Depth of projectile penetration versus compressive strength of the ferrocement panels

36 38 40 42 44 46 48 50

Compressive Strength (MPa)

8

10

12

14

16

18

20

22

24

De

pth

of

Pe

ntr

ati

on

(m

m)

Figure 6. Absorbed energy by different types

of specimens

Figure 7. Impact resistance of various

specimens



303

3.2 Modes of failure

After a carefully examination of the type of cracking and crushing of concrete, two

modes of damages were identified for the specimens in the present test program. As shown in

Figure 9, and also indicated in Table 5, these two modes of failure are: perforation and

scabbing. It can be observed from the said figure that the depth of crater depends on the type

of reinforcement.

As expected and regardless of the type and amount of reinforcement employed, it was

observed that the panel specimens (RP, FS1, FS2 and FH) failed in perforation mode.

Meanwhile, the panel specimens (FP1, FP2, FM, FMS, FMP and FHP) failed in scabbing.

Results found from impact resistance tests that all specimens broke into pieces once the no. of

impact blows causes the first crack, which indicate their brittle nature. The fractures of the

specimens are clean with little debris, thus emphasizing the tensile nature of the actual failure

process, as shown in Figure 10.

The economical and environmental advantages of using reinforcement to provide

thinner road structures, longer life cycles and reduction in maintenance costs and of course

savings in natural resources due to prolonged service intervals.

B) Rear Face DamageB) Rear Face DamageB) Rear Face DamageB) Rear Face Damage

FHPFHPFHPFHP FMPFMPFMPFMP

A) Typical Front Face DaA) Typical Front Face DaA) Typical Front Face DaA) Typical Front Face Damagemagemagemage

FMSFMSFMSFMS RPRPRPRP

Figure 9. Mode of failure of the tested specimens

FS1FS1FS1FS1 FHFHFHFH



304

4. CONCLUSIONS

From the results of the experimental investigations reported herein, the following conclusions

can be drawn:

1- The advantages of employing steel wire mesh or steel fiber reinforcement appreciably

decreases depth of projectile penetration and correspondingly increases the

compressive strength of the cement mortar panels.

2- In this study, it is observed that the value of compressive strength decrease with

addition of polypropylene fiber.

3- Another objective of this study was that will provide recommendations as to best

practice use of ferrocement panel in road as a base course and improvements that

could be made to the specification.

4- Within the scope of this experimental investigation reported two mode of failure are

observed: perforation, and scabbing.

5- The drop load depth can be a reasonable indicator of cumulative damage in the case

of drop impact test.

6- The impact resistance of the ferrocement was improved with higher ratio of volume

fraction and type of fibers.

7- It was found that the ferrocement panel which was reinforced with square steel wire

meshes has the lowest depth of projectile penetration (8.7 mm) i.e. possessed superior

impact resistance, while the ferrocement panel which was reinforced with hexagonal

steel wire meshes comes next with a depth of projectile penetration (8.9 mm).

8- The cement mortar panel which was reinforced with crimped steel fibers (FS1)

reveals a low depth of projectile penetration close to that of the ferrocement panels

(9.0 mm) i.e. comparable impact resistance.

9- The cement mortar panel which was reinforced with polypropylene fibers (FP1) has

the highest depth of penetration (23.3mm) which indicates that such polymeric fiber

reinforcement does not enhance impact resistance if measured by the present

projectile penetration depth method.

Figure 10. Damages of specimens under impact load

FHSFHSFHSFHS RPRPRPRP



305

REFERENCES

1. ACI Committee 544, 1988, "Measurement of Properties of Fiber Reinforced Concrete",

ACI Materials Journal, Vol.85, No.6, Nov.-Dec., pp.583-593.

2. Banthia, N.; Yan, C. and Sakai, K., 1998, "Impact Resistance of Fiber Reinforced Concrete

at Subnormal Temperatures", Cement and Concrete Composites, Vol.20, pp.393-404.

3. Barr, B. and Baghli, A., 1989, "A repeated Drop-weight Impact Testing Apparatus for

Concrete", Magazine of Concrete Research, Vol.40, No.144.

4. Mansur, M. A., Ahmed, I., and Paramasivam, P., 2000, "Punching Shear Behavior of

Reinforced Ferrocement Slabs", ACI Structural Journal, Vol.97, No.5, Sep.-Oct.

5. Ramakrishnan, V.; Brand Shaug, T.; Coyle, W.V. and Schrader, E.K., 1980, "A

Comparative Evaluation of Concrete Reinforced with Straight Steel Fibers and Fibers with

Deformed Ends Glued Together into Bundles", ACI Journal, Vol.77, No.3, May-June,

pp.135-143.

6. Schrader, E.K., 1981, "Impact Resistance and Test Procedure for Concrete", ACI Journal,

Vol.78, No.2, March-April, pp.141-146.

7. Swamy, R.N. and Jojagha, A.H., 1982, "Impact Resistance of Steel Fiber Reinforced

Lightweight Concrete", Journal of Cement Composites and Lightweight Concrete, Vol.4,

No.4, November, pp.209-220.

8. Gao, X. 2007, "Mix Design and Impact Response of Fibre Reinforced and Plain Reactive

Powder Concrete", M.Sc. Thesis, RMIT University, Melbourne, Australia.

9. K. Sasiekalaa and R. Malathy, “Flexural Performance of Ferrocement Laminates

Containing Silicafume and Fly Ash Reinforced with Chicken Mesh”, International Journal of

Civil Engineering & Technology (IJCIET), Volume 3, Issue 2, 2012, pp. 130 - 143, ISSN

Print: 0976 – 6308, ISSN Online: 0976 – 6316.

10. Dr. Prahallada. M.C, Dr. Prakash. K.B and Dr. Shanthappa B.C, “Effect of Redmud on

the Properties of Waste Plastic Fibre Reinforced Concrete an Experimental Investigation”,

International Journal of Civil Engineering & Technology (IJCIET), Volume 2, Issue 1, 2011,

pp. 25 - 34, ISSN Print: 0976 – 6308, ISSN Online: 0976 – 6316.

11. P.A. Ganeshwaran, Suji and S. Deepashri, “Evaluation of Mechanical Properties of Self

Compacting Concrete with Manufactured Sand and Fly Ash”, International Journal of Civil

Engineering & Technology (IJCIET), Volume 3, Issue 2, 2012, pp. 60 - 69, ISSN Print:

0976 – 6308, ISSN Online: 0976 – 6316.

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