Mechanical & Civil Engineering Departments College of Engineering Prince Mohammad Bin Fahad University I. Babbili, I. Ansari, R. Al-Roqaiti, O. Qassar, N. Qahtani, S. Aladhyani, A. Alunaiz, M. Almatrook, Dr. M. A. Al-Najjar, Dr A. Aziz and Dr. F. Djavanroodi

Objectives The aim of this research work is to give an overview of the material characterization of reinforced steel made for concrete structures in Saudi Arabia through experimentation and statistical analysis. Chemical testing with the help of number of laboratories in KSA and UK are performed on more than 70 rebar’s ASTM 615 grade 60 samples and the results is compared with the standard ASTM A 615. It is also useful to evaluate the variations in the chemical property of the rebar's produced among the manufacturers and between the heats for the same manufacturer. Statistical analysis of bar properties will be conducted to identify the variability of the chemical properties of steel reinforcing bars produced in the KSA

NoNo ChemicalsPropertyEffects on the Rebar's 1 Carbon (C) Hardness, strength, weldability, brittleness Carbon less than 0.1 percent will reduce the strength. Carbon above 0.3 percent and makes the steel bar unweldable and brittle. 2 Manganese (Mn) Strength and yield strength Higher manganese content in steel increases the tensile strength and also the carbon equivalent property. 3 Sulphur (S)brittleness. Presence of sulphur should be limited. ASTM A615 ≤ High sulphur makes the bar brittle during twisting, makes hot shot problem during rolling 4 Phosphorus (P) strength and brittleness High phosphorus content increase in strength, corrosion resistance and brittleness. 5 Copper (Cu) Strength and corrosion resistance High content of copper increases the strength and resistance corrosion 6 Chromium (Cr) Weldability and corrosion resistance Present as an impurity from the scrap and influences carbon equivalent; weldability and increases corrosion resistance property. 7 Carbon Equivalent (CE or Ceq) Hardness, tensile Strength, weldability Effects the TMT (Thermo mechanically treated) process parameter. For CTD (Cold twisted deformed) bars, it has a maximum limit of % Influence of different chemical ingredients in steel on properties of rebar's

Experimental work Sample collection: List of rebar's manufacturers which their product were tested UsaimiSABICAl RajhiAl IttefaqJaziraWataniaTaybahAl Yamamah USHARAITJAWATAYA 4

CHEMICAL ANALYSIS TESTS 5 The testing were performed at three different laboratories: 1. Saudi Arabia Standard Organization (SASO) 2. SABIC, Saudi Basic Industries Corporation 3. Imperial College London To test for chemical composition the specimens were grinded prior to chemical analysis. The spectrometer test or spark test were used to test the samples. Foundry Master X-line as shown in the figure was used for testing. This machine can analyze up to 27 different chemical components. FOUNDRY-MASTER X line

Results and Discussion The percentage average of elements are: % Average Carbon = 0.26% Average Phosphors = 0.02, % Average Sulphuer = % Average Copper = 0.079, % Average Chromium = 0.061, % Average Manganese = % Average Carbon Equivalent contents Sample of test results for chemical composition A 615 Grade 60 Reinforcement steel rebar’s. 6 Sample Id.Size(mm)CPSCuCrMoNiVSiMnCE_1 US US US US US US US US US US

Results and Discussion cont.. ElementsC%P%S%Cu%Cr%Mo%Ni%V%Si%Mn% Maximum Minimum Average Median Standard deviation Statistical analysis of the chemical composition of A 615 grade 60 steel rebar’s The standard deviation for all the elements are considerable indicating indicating large variations in raw materials (probably the scrap metal quality used)

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Conclusions Chemical composition tests conducted on 71 samples of locally manufactured steel reinforcing rebar’s in Saudi Arabia. The results of the tests have shown that less than 3% of the steel failed to meet minimum ASTM standards for chemical composition. It is evident that, for most bars sizes of A 615 Grades 60, the mean for the chemical composition is not situated at the midpoint of the data range, indicating non- normal distributions, therefore, the characteristic chemical composition of locally produced steel bars is not consistent 10

Acknowledgment: The Industrial collaborators Saudi Arabia Standard Organization (SASO) SABIC, Saudi Basic Industries Corporation Al Ittifaq steel Finally we thank our colleges for their valuable input that assisted the research Dr K. F. Al-Hajeri, Mr M. Yaghoub at SABIC, Dr. M. M. Al Motari at SASO and Mr H. M. Dowla at Al Ittifaq steel. 11

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