Ibrahim Mohammed

• Doctor of Philosophy
• Engineer at King Fahd University of Petroleum and Minerals

This study explores the enhanced performance and sustainability of polymer enhanced concrete, focusing on polymer concrete (PC) by incorporating synthetic polymers, including polyethylene, polypropylene, polystyrene, and polyvinyl chloride. Distinguished by synthetic polymeric binders, PC demonstrates superior attributes, such as improved strength-...

The primary concern for the durability of ordinary Portland cement concrete is the breakdown of calcium silicate hydrate (C-S-H) formed during hydration when exposed to sulfate environments. The disintegration mechanisms of the binder structure in alkali-activated concrete (AAC) derived from aluminosiliceous precursors may vary, owing to the distin...

Lithium batteries are increasingly used to store energy, but are limited by high cost, safety concerns, leaking of electrolytes, and low capacity. Recently, cement-based batteries have emerged as a viable alternative to lithium batteries. Indeed, the porous structure of cement and cement microcracks provide routes for ionic solutions to pass throug...

Globally, there has been a lack of sustained efforts by different industries to decarbonize the environment. Research on building materials has focused on the synthesis of alternative cement-free binders utilizing industrial by-products and natural materials to reduce greenhouse gases generated from cement production. Alkali-activated binder (AAB)...

The effect of admixing nanosilica on the fresh and hardened properties of natural pozzolan (NP) based alkali activated concrete (AAC) was examined. The workability, setting times, engineering properties, durability characteristics and pore structure of concrete were evaluated. In addition, the polymerization mechanism was assessed by SEM and XRD an...

In recent years, bacteria-based self-healing concrete has been widely exploited to improve the compressive strength of concrete using different bacterial species. However, both the identification of the optimal involved reaction parameters and theoretical framework information are still limited. In the present study, both experimentally and numeric...

This paper presents the results of a study conducted to synthesize alkali-activated mortars (AAMs) at room temperature. The AAMs were prepared using silicomanganese fume (SiMnF) and ground granulated blast furnace slag (GGBFS) as precursor materials (PMs) and sodium hydroxide (NaOH) and sodium silicate (Na2SiO3) as alkaline activators (AAs). The co...

Although the synthesis and properties of natural pozzolan (NP)-based alkali-activated binder (AAB) have been investigated, to the best of our knowledge, no study has focused on and assessed the performance of such concrete when exposed to acid attack. In addition, there is a lack of information regarding the optimisation of reaction parameters. The...

The impact of microbial calcium carbonate on concrete strength has been extensively evaluated in the literature. However, there is no predicted equation for the compressive strength of concrete incorporating ureolytic bacteria. Therefore, in the present study, 69 experimental tests were taken into account to introduce a new predicted mathematical f...

Bio-inspired self-healing of concrete cracks has been widely exploited to improve concrete properties and thus increase concrete life span using different bacterial species in recent years. The most common bacterial species found in the present literature are B. sphaericus, Sporosarcina pasteurii, Spore-forming alkali-resistant bacteria, B. megater...

Alkali activated binders (AABs) are evolving as alternative to Portland cement. They are predominantly synthesized using aluminosilicate materials, such as fly ash, silica fume, metakaolin, etc. However, the synthesis of these binders is very sensitive to several factors. These include the source, constituents and fineness of the precursor material...

This study focuses on the development of durable structural lightweight concrete (LWC) by incorporating expanded perlite aggregate (EPA) in the range of 0 to 20% by weight. In order to ensure its durability when exposed to chloride environment, concrete was produced with low water-to-cement ratio and ordinary Portland cement (OPC) was replaced with...

Durability of emerging alkali-activated binder (AAB) widely viewed as alternative to ordinary Portland cement (OPC) is yet to be fully understood particularly when exposed to chloride-contaminated service environment. In this study, the resistance of natural pozzolan (NP) based alkali activated concrete (AAC) incorporating nanosilica (nSiO 2) to ch...

Durability of emerging alkali-activated binder (AAB) widely viewed as alternative to ordinary Portland cement (OPC) is yet to be fully understood particularly when exposed to chloride-contaminated service environment. In this study, the resistance of natural pozzolan (NP) based alkali activated concrete (AAC) incorporating nanosilica (nSiO2) to chl...

Background Gastric cancer has a low overall survival rate worldwide, and surgery remains the only intent to cure option at the early stages of the disease. HER-2 positive cancers may have a survival advantage. We present a patient with stage IV gastric cancer HER-2 positive responsive to Herceptin, free of detectable disease two years after surgery...

The chemical constituents of precursor materials, the composition and concentration of alkaline activators, volume of free water, and curing conditions are some of the mix design variables that influence the fresh and hardened properties of alkali-activated binders (AABs). To achieve desirable engineering properties and long-term performance of an...

The strength gain of alkali-activated binders (AAB) when cured at room temperature is delayed due to the slow polymerization process. This is the major impediment in the utilization of this green concrete in cast in-situ concrete structures. In order to expand the applications of these binders to various fields of construction, attempts have to be...

The present study aims to evaluate the antioxidant and antibacterial activity of ethanol extracts from gamma-irradiated pomegranate (Punica granatum) peel powder (PE) at the dose levels of 0, 3, 6, and 9 kGy. The аntioxidant activity of the extracts was estimated using the radical scavenging activity against 2,2′-diphenyl-1-picrylhydrazyl (DPPH•),...

This study assessed the flow criteria, compressive strength, and durability (chloride permeability, corrosion and sulfate resistance) characteristics of self-compacting concrete (SCC) prepared utilizing crushed limestone powder (CLSP). The test samples were prepared by partially replacing CLSP with cement and aggregate such that CLSP/(CLSP + Cement...

This paper reports the results of a research study conducted to evaluate the effect of curing methods on the mechanical properties of ordinary Portland cement (OPC) and Silica Fume Cement (SFC) concretes. Slab and beam specimens were prepared and cured by covering them with wet burlap or applying a curing compound under field conditions. Four types...

Heavyweight concrete, prepared with a mixture of concrete and heavyweight aggregates or metallic components, is generally used for radiation shielding purposes. In the present study the radiation shielding properties of concrete prepared with electric arc furnace slag aggregates (EAFSAs) and steel shots, was investigated. The results indicated that...

This paper presents the results of a study conducted to evaluate the corrosion protection provided by chemical inhibitors to the fusion bonded epoxy coated (FBEC) steel bars with surface damage. FBEC bars with 0%, 1%, 2%, or 4% damage to the coating were utilized to prepare concrete specimens contaminated with 0%, 0.4%, 1%, and 2% chloride by weigh...

This paper presents results of a study conducted to evaluate the mechanical properties and durability characteristics of ordinary Portland cement (OPC) and blended cement (silica fume and fly ash) concrete specimens prepared with electric arc furnace dust (EAFD). Concrete specimens were prepared with and without EAFD. In the silica fume cement conc...

The use of supplementary cementing materials, such as silica fume, fly ash, blast furnace slag, and natural pozzolans, has been promoted by their technical and economic advantages. However, in certain parts of the world, where these materials are not available locally, their utilization is solely based on their technical superiority. The practice i...

This paper reports results of a study conducted to investigate the effect of dust, contributed by the coarse aggregates, on the corrosion of reinforcing steel in concrete. The concrete specimens were prepared with up to 10% dust in the coarse aggregates. Two other batches of reinforced concrete specimens were also prepared. In one batch of specimen...

This paper reports results of a study conducted to evaluate certain mechanical properties and durability characteristics of blended cement concretes, such as silica fume, fly ash and blastfurnace slag, incorporating up to 15% cement kiln dust. The results indicate that the compressive strength of silica fume and fly ash cement concretes with up to...

Effect of a pre-packaged non-shrinkage cementitious grout on corrosion of patch repaired reinforced concrete was investigated in laboratory and field. For laboratory study, reinforced concrete specimens were monitored for corrosion, under accelerated and freely corroding conditions. Corrosion activity on freely corroding steel bars in reinforced co...

Large quantity of dust, commonly known as cement kiln dust (CKD), is produced during the production of Portland cement. In order to meet environmental requirements, CKD is disposed off in land fills. Recently, there has been a trend of utilizing it for soil stabilization, treatment of sewage, etc. Also, attempts were made at using it in cement prod...

Supplementary cementing materials (SCMs) are widely used these days to improve the durability of concrete. Silica fume has gained world wide acceptance due to its high pozzolanic reactivity compared to other SCMs. While silica fume cement concrete has several advantages over other blended cement concretes its main draw back is increased plastic and...

This paper presents results of a study conducted to evaluate the effect of chloride concentration in soil on corrosion of reinforcing steel in concrete. Concrete specimens prepared with Type I, Type V and silica fume cements were exposed to soil with a chloride concentration of up to 3%. The effect of chloride concentration in soil on corrosion of...

This paper reports results of a study conducted to assess the performance of commonly utilized repair systems when exposed to some selected exposure conditions, such as marine, belowground, fire, acid, and sulfur fumes. The performance of the selected repair systems was assessed by exposing large-sized repaired concrete specimens to the selected ex...

This long-term research was conducted to evaluate the effect of holidays, surface damage, and chloride contamination on corrosion of fusion-bonded epoxy-coated (FBEC) steel bars. The effect of surface damage or pinholes and chloride contamination on corrosion of the metal substrate was evaluated by electrochemical and gravimetric weight loss techni...

Several methods and materials, such as high performance coatings, fiber glass reinforced linings, special mortars, brick or ceramic linings, etc., are used to protect concrete from sulfuric acid attack in a sewage environment. Two proprietary high alumina cementitious lining materials, CC and SC, are recent additions to the list of protective mater...

This study was conducted to evaluate the mechanical properties and durability characteristics of nine polymer- and cement-based repair mortars. Mechanical properties, such as compressive, tensile and flexural strength, elastic modulus, shrinkage and thermal expansion were studied. The durability characteristics of the repair materials were evaluate...

Concrete deterioration due to sulfate attack is the second major durability problem, after reinforcement corrosion. This type of deterioration is noted in the structures exposed to sulfate-bearing soils and groundwater. Though concrete deterioration due to sulfate attack is reported from many countries, the mechanisms of sulfate attack have not bee...

Steel slag is produced as a by-product during the oxidation of steel pellets in an electric arc furnace. This by-product that mainly consists of calcium carbonate is broken down to smaller sizes to be used as aggregates in asphalt and concrete. They are particularly useful in areas where good-quality aggregate is scarce. This research study was con...

This paper reports the results of a study conducted to evaluate steel reinforcement corrosion and some physical properties of concrete specimens coated with two polymer-based, a cement-based polymer-modified, and a cement-based waterproofing coatings. The coated and uncoated concrete specimens were subjected to accelerated corrosion to determine th...

The effectiveness of concrete surface treatment materials such as silanes, siloxanes, etc., in preventing concrete deterioration due to sulfate attack, carbonation, and chloride-induced reinforcement corrosion was investigated. The effectiveness of these materials in decreasing the sulfate attack was evaluated by measuring the reduction in compress...

The effectiveness of concrete surface treatment materials, such as silane, siloxane, acrylic coating, etc., in reducing chloride-induced reinforcement corrosion was investigated. Two sets of reinforced concrete specimens were cast. In the first set, reinforcement corrosion was accelerated by impressing an anodic potential of 2 V and the time to cra...

1-heniain objective of (he present study was to identify the social and evironmental aspects of kerosene poisoning in children, at King Abdulaziz Hospital (KAH). Jedat. An open-ended questionnaire to the attending member of the family: by the attending physician in emergency was carried out in the Emergency Department KAH. during the period from Ap...

Hydraulic and water retaining structures are made with a huge quantity of concrete. Design life of such hydraulic structure should be large compared to normal concrete structure. Durability of concrete is an important factor affecting the strength of concrete as well as design life of hydraulic structure. Permeability of concrete affects the durabi...