Prompt Gamma Application

inBuilding Construction

IndustryA. A. Naqvi*, O.S. B. Al-Amoudi**, M.

Maslehuddin****Department of Physics, **Department of

Civil Engineering, ***Center for Engineering Research, Research Institute

King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia

Talk Outline

Introduction

Prompt Gamma Neutron Activation Analysis (PGNAA) technique

Assessment of calcium, silicon, chlorine and sulfur in concrete using :

KFUPM 350 keV accelerator-based PGNAA setup KFUPM Portable accelerator-based PGNAA

setup

PGNAA technique

Bombardment of atoms in a sample with thermal neutrons

Emission of element characteristic prompt -rays from the sample

Intensity measurement of the prompt -rays

Determination of elemental composition of the sample from measured intensity of characteristic prompt -rays

KFUPM PGNAA Setup

Basic Features

Thermal neutron capture based PGNAA setup

2.8 MeV neutrons from D(d,n) reaction

10-30 μA pulsed deuteron beam to improve peak/back ground ratio in -ray spectrum

Rectangular paraffin & High density Polyethylene based Neutron Moderator

Large cylindrical sample weighing few kg

10"x 10“ NaI detector PGNAA sample size

calculations through Monte Carlo simulations

KFUPM PGNAA setup Neutron generator Hall

KFUPM Accelerator based PGNAA Setup

KFUPM Accelerator-based PGNAA Setup

Some Selected Studiesconducted using KFUPM PGNAA Lab.

setup

Measurement of lime/silica ratio in concrete

Measurement of fly ash concentration in concrete

Chloride Contamination Assessment in the Portland cement Sample

Chloride Contamination Assessment in the plain cement concrete samples

Chloride Contamination Assessment in the fly ash, silica fume and blast furnace slag cement concrete samples

Sulfur concentration Assessment in concrete

Lime/Silica-Ratioconducted using KFUPM PGNAA Lab.

setup

Lime/Silica Ratio Measurements

Measurement of intensity of silicon and calcium prompt gamma rays from concrete

Lime/Silica ratiocalculation from

intensities ratios

Lime/Silica-Ratioconducted using KFUPM PGNAA Lab.

setup

Measurement of fly ash concentration in concrete

containing 5 and 80 wt. % fly ash

Element (wt. %)

Sample5 wt.%-FA

Sample80 wt. %-FA

H 1.03 0.762

C 5.98 4.89

O 52.19 49.6

Mg 0.28 0.45

Al 0.49 2.09

Si 15.31 16.04

S 0.187 0.25

K 0.162 0.13

Ca 23.93 21.71

Fe 0.36 0.81

27000

28000

29000

30000

31000

0 10 20 30 40 50 60 70 80

Fly Ash Concentration (wt. %)

6.42

MeV

Pro

mpt

Gam

ma

Ray

Exp.

Yie

ld

Measurement of fly ash concentration in concrete

Calcium Prompt Gamma Ray yield from Fly ash cement based concrete specimen containing 5 -80 wt. % fly ash

26000

26500

27000

27500

28000

28500

0 10 20 30 40 50 60 70 80

Fly Ash Concentration (wt. %)

3.54

MeV

Pro

mpt

Gam

ma

Ray

Exp.

Yie

ld

Chloride Contamination Assessment in the Portland cement Sample through 1.165 MeV Chlorine Gamma Ray

The enlarged view of the less interfering 1.165 MeV chlorine prompt -rays spectra for the Portland cement sample containing 1-4 wt % chlorine concentration.

1.0 wt. % chlorine concentration ( bottom most spectrum), 2 wt % chlorine concentration ( next to bottom most spectrum), 3 wt. % chlorine concentration (next to top most spectrum) and 4 wt. % chlorine concentration ( top most spectrum) .

Chloride Contamination Assessment in the Portland Cement Sample

The chlorine Prompt gamma ray measurements from Portland cement sample containing 0.2-4.0 wt. % chloride contamination.

Strong Interference of chlorine gamma rays with energy above 3 MeV with those from calcium in concrete

Chloride contamination assessment in the plain cement

concrete Sample

Chlorine Assessment in Concrete Specimen

The minimum detection limit MDC of chlorine in concrete using for 1.165 and 7.413 MeV chlorine gamma rays is 0.054 0.025 wt %

The maximum permissible limit of chlorine concentration in concrete set by the American Concrete Institute is 0.03 wt. %.

Within a statistical uncertainty of 0.025 wt.%, the MDC within the maximum permissible limit of 0.03 wt. % of chlorine set by ACI Standards.

0

40000

80000

120000

0 1 2 3

Chlorine Concentration (wt. %)

Exp.

Yie

ld-7

.413

MeV

Gam

ma

Ray

Exp.-Yield-7.413

Monte-Carlo-Fit-7.413

Chloride Contamination Assessment in the fly ash, silica fume and blast furnace slag cement concrete samples

Chlorine Assessment in Silica fume cement concrete

Chlorine Assessment in Fly Ash cement concrete

Chlorine Assessment in Blast Furnace Slag cement concrete

E

(MeV)MDC

(wt. %) in blast furnace slag concrete

[8]

MDC

(wt. %) in fly

ash cement

concrete [10]

MDC (wt. %) in silica fumes cement

concrete

1.16 -0.0220.007

0.0210.009

1.94 -0.0510.015

0.0380.011

5.72 --

-

6.11 0.034 0.0110.038 0.017

0.026 0.008

6.62 0.038 0.0120.059 0.027

0.058 0.018

7.41 0.044 0.0130.050 0.027

0.026 0.008

7.79 0.060 0.0180.076 0.029

0.063 0.019

8.58 0.076 0.0230.068 0.029

0.081 0.025

Sulfur Concentration Assessment in concrete samples

Measurement of sulfur concentration in concrete specimen using 5.421 MeV gamma ray.

Concrete samples containing 2.0-8.0 wt. % sulfur

Interference of the 5.421 MeV sulfur peak with the double escape peak of calcium.

The highest 5.421 MeV peak in (6 wt. % conc.), while the smallest peak (2 wt. conc.), % and the middle (4 wt. %. conc.)

Sulfur Assessment in Concrete Samples

The MDC of sulfur concentration in concrete for the KFUPM PGNAA setup using the sulfur 5.421 MeV prompt gamma ray =

0.6000.187 wt %.

MDC is close to the minimum limit of 0.60 wt. % of sulfur in concrete set by British Standards .

0

10000

20000

30000

40000

0 2 4 6 8 10

5.42

MeV

Gam

ma R

ay E

xper

imen

tal

Yiel

d

Sulfur concentration (wt. %)

Exp. Yield-5.42 MeV

Monte Carlo fit-5.42 MeV

Assessment of calcium, silicon, and chlorine in

concrete using Portable accelerator-based PGNAA

setup

MP320 Portable Neutron Generator Based

PGNAA Setup for Field Measurement

Portable Neutron Generator Model: MP 320 for field applications

Digital systemLight weight : 10 kg

unit easily integrated into analysis systems, 24 Vdc input, < 75 watts

Less than 500 ns rise time/fall time on source pulse

RS-232 interface works with any PC

Max. Yield:1x108 n/sMax. Lifetime: +1200 hoursPulse Rate: 250 Hz to 20 kHzPulse Width:Variable, > 5 msDuty Factor:Variable, 5 to 100%

Portable Neutron Generator Model: MP 320 for field applications

Portable Neutron Generator Model: MP 320 for field applications

Portable Neutron Generator Model: MP 320 for field applications

Portable Neutron Generator Model: MP 320 for field applications

Portable Neutron Generator Model: MP 320 for field

applications

Portable Neutron Generator –chloride assessment in Fly ash cement

concrete

Portable Neutron Generator –chloride assessment in Fly ash cement concrete

Portable Neutron Generator –chloride assessment in Blast Furnace Slag cement concrete

Portable Neutron Generator –chloride assesment in Super Pozz cement concrete

Portable Neutron Generator –chloride calibration curve for FA, BFS and SPZ cement concrete

Gamma-RayEnergy (MeV)

Minimum Detectable Concentration (MDC), % of cement

FA Concrete BFS Concrete SPZ Concrete

2.86+3.12 0.033±0.010

0.034±0.010 0.032±0.012

5.72 0.031±0.010

0.032±0.010 0.037±0.012

6.11 0.032±0.010

0.033±0.010 0.035±0.012

Portable Neutron Generator –MDC limit for chloride assessment in FA, BFS and SPZ

cement concrete

Patent Papers under processing for

Portable Neutron Generator based PGNAA Setup for onsite concrete

analysis

Thank You very much