Papers by Alfarabi Sharif
Construction and Building Materials, 2011
This paper presents results of a study conducted to evaluate the mechanical properties and durabi... more 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 concrete, silica fume constituted 8% of the total cementitious material while fly ash cement concrete contained 30% fly ash. EAFD was added as 2% replacement of cement in the OPC concrete and 2% replacement of the total cementitious content in the blended cement concretes. Mechanical properties, such as compressive strength, drying shrinkage, initial and final setting time, and slump retention were determined. The durability characteristics were evaluated by measuring water absorption, chloride permeability, and reinforcement corrosion. The initial and final setting time and slump retention increased due to the incorporation of EAFD in both OPC and blended cement concretes. The drying shrinkage of EAFD cement concrete specimens was more than that of concrete specimens without EAFD. The incorporation of EAFD was beneficial to OPC concrete in terms of strength gain while such a gain was not noted in the blended cement concretes. However, the strength differential between the blended cement concretes with EAFD and the corresponding concretes without EAFD was not that significant. The water absorption and chloride permeability, however, decreased due to the incorporation of EAFD in both the OPC and blended cement concretes. The corrosion resistance of OPC and blended cement concrete specimens increased due to the addition of EAFD.
Cement & Concrete Composites, 2003
Concrete deterioration due to sulfate attack is the second major durability problem, after reinfo... more 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 been thoroughly investigated, particularly the effect of sulfate concentration and the cation type associated with the sulfate ions on concrete deterioration. This study was conducted to evaluate the performance of plain and blended cements exposed to varying concentrations of sodium sulfate for up to 24 months. Four types of cements, namely Type I, Type V, Type I plus silica fume and Type I plus fly ash, were exposed to five sodium sulfate solutions with sulfate concentrations of 1%, 1.5%, 2%, 2.5% and 4%. These concentrations are representative of the sulfate concentration in highly saline soils. The sulfate resistance was evaluated by visual examination and measuring the and reduction in compressive strength. The maximum deterioration, due to sulfate attack, was noted in Type I cement followed by silica fume and Type V cements. The performance of Type V, Type I plus silica fume and Type I plus fly ash was not significantly different from each other. The enhanced sulfate resistance noted in the Type I cement blended with either silica fume or fly ash indicates the usefulness of these cements in both sulfate and sulfate plus chloride environments.
Construction and Building Materials, 2009
This paper presents the results of a study conducted to evaluate the improvement in corrosion-res... more This paper presents the results of a study conducted to evaluate the improvement in corrosion-resistance of chloride-contaminated silica fume cement concrete due to the use of corrosion inhibitors. Three proprietary and one generic corrosion inhibitors were evaluated for their performance in inhibiting reinforcement corrosion in the silica fume cement concrete specimens contaminated with 0.4%, 1%, and 2% chloride concentration, by weight of cement. Some of the specimens were subjected to wetting and drying cycles and reinforcement corrosion was monitored by measuring corrosion potentials and corrosion current density. Another batch of concrete specimens was partially immersed in the chloride solution and reinforcement corrosion was accelerated by impressing an anodic potential of 2 V. The extent of corrosion increased with increasing chloride contamination in the concrete specimens. Incorporation of inhibitor generally decreased the rate of reinforcement corrosion. The rate of reinforcement corrosion in the concrete specimens incorporating an organic inhibitor that was added to the concrete during mixing was the least followed by that in the concrete specimens on which a penetrating corrosion inhibitor was applied. Further, the accelerated impressed current technique was noted to be suitable for quickly screening the performance of corrosion inhibitors.
Construction and Building Materials, 2003
Steel slag is produced as a by-product during the oxidation of steel pellets in an electric arc f... more 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 conducted to evaluate the mechanical properties and durability characteristics of steel slag aggregate concrete in comparison with the crushed limestone stone aggregate concrete. The durability performance of both steel slag and crushed limestone aggregate concretes was evaluated by assessing water permeability, pulse velocity, dimensional stability and reinforcement corrosion. The results indicated that the durability characteristics of steel slag cement concretes were better than those of crushed limestone aggregate concrete. Similarly, some of the physical properties of steel slag aggregate concrete were better than those of crushed limestone aggregate concrete, though the unit weight of the former was more than that of the latter.
Advances in Cement Research, 2007
Cement Concrete and Aggregates, 1998
Construction and Building Materials, 2009
This paper reports results of a study conducted to assess the properties of cement kiln dust (CKD... more This paper reports results of a study conducted to assess the properties of cement kiln dust (CKD) blended cement concretes. Cement concrete specimens were prepared with 0%, 5%, 10%, and 15% CKD, replacing ASTM C 150 Type I and Type V. The mechanical properties of CKD concrete specimens were evaluated by measuring compressive strength and drying shrinkage while the durability characteristics were assessed by evaluating chloride permeability and electrical resistivity. The compressive strength of concrete specimens decreased with the quantity of CKD. However, there was no significant difference in the compressive strength of 0 and 5% CKD cement concretes. A similar trend was noted in the drying shrinkage strain. The chloride permeability increased and the electrical resistivity decreased due to the incorporation of CKD. The performance of concrete with 5% CKD was almost similar to that of concrete without CKD. Therefore, it is suggested to limit the amount of CKD in concrete to 5% since the chloride permeability and electrical resistivity data indicated that the chances of reinforcement corrosion would increase with 10% and 15% CKD.
Journal of Materials in Civil Engineering, 1991
Journal of Composites for Construction, 2015
Aci Structural Journal
This paper presents comprehensive data and their interpretation on the plate bonding repair techn... more This paper presents comprehensive data and their interpretation on the plate bonding repair technique in terms of effects of plate thickness and end anchorage on ductility, ultimate load, and mode of failure. Reinforced concrete (RC) beams were preloaded to 85 percent of their ultimate capacity and subsequently repaired by bonding steel plates of different thicknesses with and without end anchorages. Anchor bolts were used for end anchorages. The repaired beams showed higher strength than the original beams, provided the plates did not exceed a certain limiting thickness. Increasing the plate thickness changed the mode of failure of the repaired beams from flexural to premature failure, developed due to shear and/or tearing of the plate, causing a reduction in ductility. End anchorages to the bonded plates could not prevent the premature failure of the beams but improved ductility with decreasing significance as the plate thickness increased, and yielded a marginal improvement in ul...
Reduction in the useful service-life of reinforced concrete construction, mainly due to reinforce... more Reduction in the useful service-life of reinforced concrete construction, mainly due to reinforcement corrosion, is a major problem facing the construction industry worldwide, in general, and the Arabian Gulf in particular. Deteriorating structures need to be repaired not only to utilize them for their intended service-life but also to assure the safety and serviceability of the associated components. While several repair materials are used for repair and rehabilitation of the deteriorated concrete structures worldwide, their performance in the Arabian Gulf environment, dominated by the extreme temperatures and aridity, has not been thoroughly investigated. This paper reports the results of a study conducted to evaluate the performance of repair materials available in the local market. Based on the data developed in the study, criteria for the selection of repair materials are recommended.
In the severe environmental exposure conditions that prevail in the Arabian Gulf region, durabili... more In the severe environmental exposure conditions that prevail in the Arabian Gulf region, durability is still the most important factor for the service life of most concrete structures, both in terms of economy and safety. Of the various types of deterioration mechanisms, reinforcement corrosion is at present considered to be the main cause of premature failure of reinforced concrete structures in most countries. Field exposure station has been established at Khaleej Mardomah in Jubail Industrial City to gain practical knowledge on how to produce and protect concrete structures under natural and long term exposure conditions. This field station is the first of its kind in the region. Exposure conditions include aggressive ground-water, marine environment (submerged, splash zone and zone above sea water), and outdoor exposure in air. The study involves casting different concrete specimens using different design and protection parameters, including cement type, water/cement ratio, pozz...
This paper presents results of a study conducted to evaluate the effect of aggregate quality, par... more This paper presents results of a study conducted to evaluate the effect of aggregate quality, particularly when they do not comply with the standard requirements, on the properties of concrete. Crushed limestone aggregates from six quarries, five of which did not satisfy one or more of the ASTM C 33 requirements, were utilized to prepare concrete specimens. The concrete specimens were tested to evaluate the mechanical properties, and sulfate-and corrosion-resistance. The results indicate that some of the drawbacks in terms of the C 33 criteria did not affect the physical properties and durability performance of concrete. The excessive magnesium soundness loss noted in some of the aggregates also did not influence the sulfate resistance of concrete.
The use of glass fiber reinforced plastic (GFRP) reinforcement as a building construction materia... more The use of glass fiber reinforced plastic (GFRP) reinforcement as a building construction material has increased in recent years. In particular, GFRP reinforcement for concrete has recently been developed and introduced into the international market. The assessment of the durability performance of GFRP reinforcement in harsh environments is of primer importance in order to promote the utilization of this material in concrete construction. The paper presents the scope, objectives and preliminary results of on-going extensive research program at KFUPM on the durability performance of GFRP reinforcement bars. The preliminary results cover the durability performance of one type of GFRP bars after 3 and 6 months under harsh environments both as stand-alone and with concrete. The exposure solutions include alkaline, alkaline + chloride, acid, seawater and sabkha, in addition to out-door exposure.
Engineering Computations, 1995
ABSTRACT This paper presents a finite element model for analysis of damaged RC beams strengthened... more ABSTRACT This paper presents a finite element model for analysis of damaged RC beams strengthened or repaired by externally bonding glass fibre reinforced plastics (GFRP) on the tension side of the beams. The salient features include: (i) the introduction of a thin, six—noded element to simulate behaviour of the concrete/epoxy glue/GFRP interface and )ii( a scheme of loading a virgin RC beam to a prescribed displacement to simulate damage, unloading and then reloading the damaged RC beam fortified by an externally bonded GFRP plate. Results are presented for RC beams repaired by plates of varying thickness and a transmutation of failure mode is noted from classical flexure for the case of external reinforcement in the form of thin GFRP plates to a unique concrete cover rip off failure for thicker GFRP plates and not predicted by the ACI shear strength formula for diagonal tension failure of unplated RC beams of similar geometry.
Concrete Solutions 2014, 2014
Materials and Structures, 1995
... Other advantages include its small size and the fact that it can be reused. The only test var... more ... Other advantages include its small size and the fact that it can be reused. The only test variable studied Table 1 Concrete mix design ... A two-component epoxy adhesive was used to bond theplates to the surface of the concrete block. 2.3 Bonding procedure ...
Magazine of Concrete Research, 1995
... The repair and strengthening of damaged reinforced concrete (RC) beams using externally bonde... more ... The repair and strengthening of damaged reinforced concrete (RC) beams using externally bonded steel ... of all repaired beams was increased and the degraded stifiess of the beams was restored. However, the failure was sudden due to plate separation for most repaired beams ...
Magazine of Concrete Research, 1995
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Papers by Alfarabi Sharif