Assessment on engineering properties and CO2 emissions of recycled aggregate concrete incorporating waste products as supplements to Portland cement

This paper presents an experimental investigation on the durability properties and carbon dioxide (CO2) emissions of concrete developed using waste products. The concrete comprised of recycled concrete aggregate (RA) as a complete coarse aggregate replacement. In addition, rice husk ash (RHA), palm oil fuel ash (POFA) and palm oil clinker powder (POCP) were used as replacement materials for cement at levels up to 30%. The supplementary cementitious materials (SCMs) were used in RA concrete with the aim of reducing the dependency on cement as a stand-alone binder. The compressive strength, water absorption, chloride-ion penetration and electrical resistivity were investigated for RA concrete containing SCMs. Moreover, the residual compressive strength was also examined along with the weight loss to check the elevated temperature resistance of RA concrete with SCMs. The results revealed that

Microstructural investigation and durability performance of high volume industrial by-products-based masonry mortars

The use of eco-efficient building materials in construction has become a trend in regard to the effort of mitigating the effect of global warming which include CO2 emission, energy demand, and natural resources depletion that lead to negative environmental impacts. The present study was attempts to investigate the microstructure behaviour and durability performance of masonry mortars. In this context, palm oil clinker powder (POCP) was utilised to replace cement up to 80%, while the incinerated bottom ash aggregates (IBAA) was utilised to replace mining sand up to 100%. Eventually, further investigation was carried out on the durability performance through water absorption, sorptivity, sulphate attack, and electrical resistivity on the ideal mixtures of 40% of POCP (CLP) and IBAA with 50% (CLPI50) & 100% (CLPI) mixtures. As a result, irregular shape of POCP particles in SEM and the presence of high silica in POCP were observed to produce the peaks of portlandite as well as early occurrence of calcite. In this case, IBAA particles have angular, while porous microstructure in SEM and the XRD results showed high peaks of quartz and calcite. The final mixes containing CLP, CLPI50, and CLPI respectively obtained 51, 56, and 61% of 28-day compressive strength of control mix (CL) that was greater than the requisite 12.4 MPa. On another note, the mix- CLP showed better durability performance (6% water absorption, 84 mm/100 cm2 of IRA) compared to CLPI50 (7%, 89 mm/100 cm2), while the drying shrinkage performance of CLP possessed similar trend to that of the CL (0.064%). Finally, the mix CLP managed to produce extremely good electrical resistivity

Performance evaluation of masonry grout containing high volume of palm oil industry by-products

The rapid depletion of natural resources has led to the need to develop sustainable practices and material in various applications. One such sustainable practice is to divert the waste generated in the palm oil industry into production of building materials. In this study, palm oil clinker (POC) is used to replace cement and coarse aggregate. The POC chunks are crushed to be used as coarse aggregate and further ground to produce POC powder (POCP) to be used as a binder. The physical properties, chemical composition and scanning electronic microscopic studies were conducted to check the feasibility of substitution of up to 50% POCP as binder and up to 100% POC as coarse aggregate. Density, ultrsonic pulse velocity(UPV), compressive strength for air & water curing, flexural, tensile strength, modulus of elasticity in water cured regimes and structural efficiency were evaluated for the samples. Carbon footprint, cost effieciency and energy savings were also evaluated to understand the contribution of POC to sustainability. The results revealed that the ideal mixture of GPP (30% POCP & 50% POC) masonry grout achieved 79% of compressive strength, a 83% of flexural strength, 85% of tensile strength and about 85.5% of modulus elasticity, as compared to control masonry grout. Carbon emissions of GPP was reduced by 21% and 14.60% cost reduction was established, in addition, appreciable energy savings was notified. The study showed that that utilisation of POC as eco-friendly material in masonry grout is highly recommended based on performance and can provide a route to sustanable practices in the building industry. © 2019 Elsevier Lt

High volume cement replacement by environmental friendly industrial by-product palm oil clinker powder in cement – lime masonry mortar

Cement-lime based mortar is extremely popular for a wide range of construction around the world and conserving natural resources used in the production of such material is of capital importance. Identification of alternative materials from palm oil based industrial by-products enabled researchers to use palm oil clinker powder (POCP) as a cement replacement material; in this research work, POCP was used as cement replacement material in masonry mortar. The physical, chemical properties and SEM of POCP were analyzed to investigate the feasibility of utilizing POCP as cement replacement for up to 80%. Based on the feasibility study, final mortar mixes were prepared utilizing 40% of POCP. Further investigations were carried on fresh, mechanical and bond properties of mortar. The hardened properties for mechanical performance and ultrasonic pulse velocity (UPV) investigated in water and air cured regimes show that up to 40% of cement could be replaced to obtain the requisite compressive strength of 12.4 MPa for cement-lime mortar. Further, POCP ground to more number of cycles had minor impact on the mechanical properties. The investigation on the potential use of POCP as cement replacement confirmed the potentiality through energy saving, cost effective and cleaner environment

Crack assessment of RC beam-column joints subjected to cyclic lateral loading using Acoustic Emission (AE): The influence of shear links aspect

Existing reinforced concrete (RC) beam-column joints that are designed mainly to resist gravity load, may encounter serious problems in low to moderate seismic regions. The moderate earthquake in Ranau affected numerous old buildings, caused by uncontrolled cracks propagation found in RC member, beam-column joint. Effects of the shear reinforcement between offset links on cracks formation on RC beam-column joints were investigated under cyclic lateral loading with acoustic emission (AE) technique monitoring. The control specimen (BCJ-1) without additional shear reinforcement showed more irregular cracks thus concrete cover spall observed at early DR level compared to other specimens with shear reinforcement between offset links. Sudden drop of AE hits beyond 2.25% DR level with significant increase in crack width showed that BCJ-1 was no longer able to resist higher loads due to de-bonding between reinforcement and concrete. From RA-AF graphs, failure was exhibited according to DR stages with respect to crack characteristics.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Assessment on engineering properties and CO2 emissions of recycled aggregate concrete incorporating waste products as supplements to Portland cement

This paper presents an experimental investigation on the durability properties and carbon dioxide (CO 2 ) emissions of concrete developed using waste products. The concrete comprised of recycled concrete aggregate (RA) as a complete coarse aggregate replacement. In addition, rice husk ash (RHA), palm oil fuel ash (POFA) and palm oil clinker powder (POCP) were used as replacement materials for cement at levels up to 30%. The supplementary cementitious materials (SCMs) were used in RA concrete with the aim of reducing the dependency on cement as a stand-alone binder. The compressive strength, water absorption, chloride-ion penetration and electrical resistivity were investigated for RA concrete containing SCMs. Moreover, the residual compressive strength was also examined along with the weight loss to check the elevated temperature resistance of RA concrete with SCMs. The results revealed that the use of 30% RHA as SCM produced the highest compressive strength efficiency of 0.143 MPa/kg cement among all mixes at the age of 90 days. In addition, a significant enhancement was observed for the durability-related properties at later ages, although the engineering properties of RA concrete containing SCMs was low at the age of 28 days. The thermogravimetric (TG) analysis indicated that the RHA is more effective as a pozzolanic additive than POFA and POCP. The CO 2 emissions from RA concrete were reduced by approximately 29% when it was incorporated with 30% SCM, where the eco-strength efficiency showed the highest values at 20% cement replacement level of 20%