The usage of waste plastics in the form of eco-bricks for the construction of buildings is gradually gaining traction. However, the performance of eco-brick masonry walls is not sufficiently known, and the process of setting up experimental rigs for the conduct of compressive strength test of masonry are usually cumbersome and expensive. This study investigated the compressive strength performance of eco-brick masonry walls and developed a predictive model for evaluating the strength of eco-brick masonry walls. Waste polyethylene terephthalate (PET) bottles were physically recycled and utilised to manufacture four samples of eco-bricks, strength grades 40.5, 21.02, 13.52 and 3.05N/mm2 using stone dust, sharp sand and laterite at predetermined moisture contents. The eco-bricks were laid with seven grades of mortar to build 54 eco-brick masonry prisms. A quasi-static compressive loading test was carried out on the masonries, and predictive models were developed using multiple non-linear regression. The study found that eco-brick masonry prisms supported large loads and failed due to the propagation of tensile cracks and debonding of the units. The study also found that the compressive strength of eco-brick masonry is a power function of the compressive strength of eco-bricks and the mortar used for the bonding. It was determined that the mean ratio of the expected to experimental prism strength was 1.002. The mathematical model developed in this study for predicting the strength of eco-brick masonries can significantly evaluate the compressive strength of eco-brick masonry.

Concrete production with waste plastics as a replacement for aggregates has continued to lead discussions on the probable solutions to plastic waste threats. However, investigation on the direct application of concrete incorporating waste plastic for the production of walling units is yet to receive the desired considerations. This study aims to evaluate the effect of fine aggregate substitution with waste plastic aggregate on concrete blocks to determine appropriate material mixes that can satisfy the requirements for application as walling material. Samples of concrete blocks were prepared using natural sand, plastic waste, cement and water at a 1:4 binder-to-aggregate ratio with consistent workability. The composite materials were tested for compressive strength, flexural strength, splitting tensile strength, elastic modulus, water absorption and sorptivity. The study found that waste PA increases the compressive strength of plastic aggregate (PA) concrete blocks at 5

Rapid urbanisation causes a rise in the need for infrastructure, which in turn fuels the creation of additional concrete and further increases cement supplies. Activation of illite-based clay mineral and usage in concrete production is one of the sustainable ways to address the cement industry anthropogenic issues. This study evaluates the durability properties of water transport (water absorption, and capillary water absorption), and resistance to aggressive environments (5% solutions of hydrochloric acid, HCl; sodium sulphate, Na2SO4; and calcium chloride, CaCl2) of meta-illite calcined clay (MCC)-based high-performance concrete (HPC). For this purpose, concrete was produced with 5, 10, 15, 20, 25 and 30% MCC content in partial substitution of CEM II. Results from the water absorption tests indicate an average percentage value of 3.57%, 3.35% and 2.52% for all the observed mixes at 28, 56 and 90 days, respectively, with MCCC-10 HPC having an average best value of 2.23% across the curing ages. On all observed days, the 5 to 15% cement replacements had very close average water sorptivity value of 0.125 ± 0.001 mm/min0.5 with the control mix (0.113 ± 0.011 mm/min0.5). The aggressive environments exposure findings of the hardened MCC-based HPC specimens of 10 to 20% recorded an approximately 15% compressive strength loss in HCl, Na2SO4 and CaCl2 solutions over the 90 days of curing. In all, the HPC mixes of 5 to 15% MCC content obtained an average durability performance factor of 89%. As a result, these findings imply that MCC can replace cement in up to 15% of HPC production.

In order to study the mechanical and microstructural properties of masonry mortar, combined particles of cockle and scallop seashell wastes were incorporated and analysed through destructive and non-destructive tests. River sand was replaced with the combined seashell particles (SPs) at seven mixes, viz., 0, 5, 10, 15, 20, 25, and 30% with a 0.5 constant water-to-cement ratio (W/C). A mortar mix design of M4-type of BS EN 1996-1-1 was adopted with a target compressive strength of 5.17 MPa at 28 days. The physical, chemical and mineralogy properties of the SPs were analysed through BS standard sieving, X-ray fluorescence (XRF), scanning electron microscopy (SEM), and X-ray diffraction (XRD) methods. The hardened SP-based mortars were subjected to direct compressive strength, rebound hammer, ultrasonic pulse velocity tests, and nonevaporable degree of hydration analysis. The XRF, SEM, and XRD analysis results of the SPs showed over 86% calcium oxide content, irregular and needle-like particles, and hydroxyapatite/calcium silicates, respectively. The direct compressive strength and the non-destructive test results revealed that up to 30% sand replacement with SP in masonry mortar, an improvement of 45% compressive strength could be attained over the control sample. The nonevaporable water method of the degree of hydration analysis showed that after 28 days, hydration increased considerably for the SP-blended mortars over the control, especially the SPM-30 with 30% sand replacement. Therefore, the study concludes that the investigated SPs in blended masonry mortar could benefit an eco-friendly environment and conservation of natural resources.

A hostel facility’s effective functioning and performance contribute significantly to advancing knowledge and technologies for a sustainable future. Therefore, post-occupancy evaluation (POE) offers the basis for promoting construction projects’ future design and construction quality. The present study thereby examines the maintenance feedback mechanisms and limiting factors of POE to address future occupants’ satisfaction in selected hostels in Nigerian universities. A quantitative research design method was adopted where 340 questionnaire instruments were administered to the student occupants and facilities managers. The data obtained were subjected to descriptive statistics using a mean score, relative importance index and ranking. The research findings revealed that the maintenance feedback mechanisms utilised both by the student and facilities manager respondents have direct communication channels with the relevant stakeholders. The limiting factors of POE analysed showed that non-availability of information on building facilities, the persistence of maintenance challenges in building, lack of commitment from school management and insignificant improvement on the maintenance challenges were severe factors to be tackled in the studied hostels. Therefore, it is recommended that Nigerian universities’ regulating bodies conduct a building performance evaluation of existing hostel facilities in Nigerian universities and update the procedures guide and physical development manual for Nigeria’s university system.

The present study examines the durability properties of Class 1 (50–75 MPa) high-performance concrete (HPC) blended with rice husk ash (RHA) as a partial replacement of CEM II B-L, 42.5 N. Six HPC mixes were prepared with RHA and used as 5%, 10%, 15%, 20%, 25%, and 30% of CEM II alone and properties are compared with control mix having only CEM II. The binders (CEM II and RHA) were investigated for particle size distribution (PSD), specific surface area (SSA), oxide compositions, mineralogical phases, morphology, and functional groups using advanced techniques of laser PSD, Brunauer–Emmett–Teller (BET), X-ray fluorescence (XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared/attenuated total reflection (FTIR/ATR), respectively, to understand their import on HPC. Durability properties, including water absorption, sorptivity, and chemical attack of the HPC samples, were investigated to realise the effect of RHA on the HPC matrix. The findings revealed that the durability properties of RHA-based HPCs exhibited an acceptable range of values consistent with relevant standards. The findings established that self-produced RHA would be beneficial as a cement replacement in HPC. As the RHA is a cost-effective agro-waste, a scalable product of RHA would be a resource for sustainable technology.

Supplementary cementitious materials (SCMs) have been widely used to enhance both the microscopic and macroscopic properties of the Portland cement (PC)–SCM composite matrix. Few studies have been undertaken to establish the gel/space ratio of meta-illite calcined clay (MCC) and rice husk ash (RHA)-based high-performance concrete (HPC) mortar. This experimental paper describes a conventional degree of hydration (non-evaporable water) and porosity routes of establishing a link amid the gel/space ratio and compressive strength of a sieved mortar from Class 1 (50–75 MPa) HPC at an early age. Using the non-evaporable water method, this paper predicted the gel/space ratio of the hardened MCC/RHA-based HPC mortars and curved fitted into Powers’ exponent equation. The results from this study revealed that MCC or RHA additions (5–30% by weight of PC) to the PC-SCM matrix led to a moderate decline in the compressive strength of the low water-binder ratio (W/B) HPC mortar. The modification aimed at void volume (superabsorbent polymers, SAP, and air) applying Bolomey’s formula and Powers’ gel/space ratio developed a suitable fitting into the Powers’ model. This experimental procedure shows feasibility to predict the MCC and RHA outcome on the compressive strength of HPC.

An experimental study was carried out to determine the properties of rice husk ash (RHA) and its effect on high-performance concrete's (HPC) mechanical and microstructural properties. RHA content was placed at 0-30% at 5% step intervals and a constant water-binder ratio (W/B) of 0.3. A slump flow test was carried out to measure the workability property of the fresh HPC. In contrast, the influence of RHA contents on compressive, splitting tensile, flexural strengths and microstructural properties were examined for the hardened HPC specimens. The X-ray fluorescence (XRF), scanning electron microscopy-energy dispersive x-ray (SEM-EDX), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy-Attenuate total reflectance (FTIR-ATR), Thermogravimetry analysis (TGA), Brunauer, Emmett and Teller (BET) specific surface area and laser diffraction particle size distribution (PSD) were used to access the feasibility of RHA in HPC. XRD and SEM/EDX techniques were conducted to investigate the hydration products and microstructure in hardened HPCs. The post-test examination showed increased compressive, splitting tensile and flexural strengths of HPC samples for a 10% RHA content mix, recording the highest compressive strength in all curing ages. As the curing ages increase, the microstructure of the samples with RHA becomes denser than the control due to the refinement of the microstructure by the RHA incorporated. The XRD and SEM/EDX confirmed the lower calcium hydroxides from pozzolanic reactivity and later formation of C-S-H. The results suggest that RHA can be used as a cement replacement for up to 10% in HPC to produce sustainable concrete.

This research characterises bamboo leaf ash (BLA), which was obtained by calcining dry bamboo leaves at approximately 600 °C for 2 h in a laboratory-controlled muffle furnace. To understand the pozzolanic potentials of the BLA, X-ray fluorescence (XRF) and scanning electron microscope/energy dispersive x-ray (SEM/EDX) techniques were employed. The BLA was then mixed with Portland cement (PC) to produce high-performance concrete (HPC) at 0, 5, 10, and 15% BLA contents by weight. Fresh HPC samples were evaluated for their workability with slump flow test. After 7, 21, 28, and 60 days of hydration, HPC samples' mechanical (compressive, splitting tensile, and flexural) and durability (water absorption, sorptivity, and influence of aggressive environments) were measured. As determined by XRF, the calcined BLA has pozzolanic properties, whereas the SEM micrograph exhibits irregular and angular morphologies. The incorporation of BLA into the HPC matrix enhanced the mechanical and durability qualities of the evaluated samples, primarily at a substitution rate of 10% PC. Therefore, it can be stated that 10% BLA can substitute cement in an HPC subjected to standard environmental conditions.

As the world population continues to increase, so does the demand for raw materials to produce basic needs of the human race. One of the areas where this pressing demand for means of production is evident is in the production of concrete materials for building construction and infrastructure. The source of constitutive materials for concrete production, such as cement and aggregates are fast shrinking across the nations of the earth, and there is an urgent need for substitutes that will guarantee the availability of this essential material to the built environment sector of the economy. One of the trending approaches is the adoption of waste materials as a replacement for some of the constitutive materials of concrete. This research reviews past works on the use of recycled plastic waste and periwinkle shells for the production of lightweight aggregate concrete. The results of this review showed that the adoption of a reduced percentage of waste plastic in concrete leads to acceptable strengths for lightweight concrete, economy, efficient energy and excellent crack resistance. The use of periwinkle shell is beneficial for satisfactory strengths for normal aggregate concrete and for lightweight aggregate concrete, excellent resistance to heat and economy. This approach is sustainable as a means of recycling and will facilitate the actualization of the sustainable development goal “Responsible Production and Consumption”, (SDGs 12). There is a perspective that combining these two waste materials will lead to improvement towards achieving sustainable concrete.

Geoelectrical resistivity imaging was integrated with cone penetrating test (CPT) and standard penetrating test (SPT) for a preliminary investigation for building construction in a foreshore environment of Ilubirin Lagos, Nigeria. The two-dimensional electrical imaging revealed two inferred geoelectrical layers of loose silty sand (80.0–400 Ωm ) and sandy clay (2.66–50.0 Ωm ). An average CPT value of 10–48 km/cm2 was measured between 0.5 and 7 m. The submerged bearing pressure ranged from 8 to 65 kN/m2. Generally, geotechnical investigations revealed the subsoils characteristics to range from soft to firm clay with low to moderate shear strength. It is recommended that a deeper pile foundation type should be adopted in the construction site so that the building would transmit their loads to a more stable basal subsoil stratum within the subsurface.

The mould-ability of concrete into intricate forms and the versatility of its constituent materials has made concrete to be the most preferred construction material. However, in developing nations such as Nigeria, poor quality of concrete is listed among the common causes of building collapse. Thus, this study investigated the effects of chemical compounds of four commonly used local ordinary Portland cement brands on the compressive strength of normal concrete. The cement was labelled brands A, B, C, and D, respectively, while all the other constituent materials remained constant in this study. The HACH DR 200 direct reading spectrophotometer method was used to analyze the composition of the oxide in each of the cement samples, while the Bogue composition formula was used to estimate the compound compositions of the cement samples. A designed mix proportion of 1:2:4 (cement: sand: granite) at water-cement ratio (w/c) of 0.6 was used to produce the concrete with an expected target strength of 25 N/mm2. Also, the initial and final setting time of the cement samples and the workability of the concrete mixes were determined. Forty-Eight (48) numbers cube samples were cast and tested for compressive strength at 3, 7, 14, and 28 curing days, respectively, using a 150 mm concrete cubes. The result shows the setting time of the cement samples to be within an acceptable period. Also, results indicated that the cement brands have a significant percentage of Tricalcium Silicate (C3S) content and low percentage Dicalcium Silicate (C2S) content responsible for faster hydration rate and higher early strength gain of the concrete. However, it was observed that a higher percentage of Tricalcium aluminate (C3A) leads to higher strength gain from 7 to 28 days of curing age.

An improved indoor environmental quality (IEQ) is a major determinant of human comfort in an occupied space. The current cross-sectional study investigates the link between indoor environmental quality (IEQ) and sick building syndrome symptoms (SBS) emergence with a case study of selected students’ hostels in a Nigerian private university. A quantitative research design method was adopted where 376 (n = 376) copies of the questionnaire were purposely administered to the student’s occupants. A mini environmental quality meter was also objectively used to measure the indoor air temperature, relative humidity, air velocity, and lighting levels in the selected hostel rooms in February and March 2019. The data obtained were subjected to descriptive and analysis of variance (ANOVA) inferential statistics using the Statistical Package for Social Sciences (SPSS) 25.0 version. The research findings revealed that students show SBS symptoms like tiredness, sensitivity to odor, sneezing, and blocked nose during their hostels’ occupancy. Meanwhile, the objective measurement results showed an average indoor temperature of 29.93 °C, 31.64 °C, and 30.71 °C. Simultaneously, average relative humidity values of 79.00%, 72.06%, and 81.01% were obtained in the monitored rooms for the morning, afternoon, and evening. The ANOVA result established a positive relationship between poor IEQ condition and the SBS symptoms of odor, stuffy nose, and nausea. Therefore, it is recommended that the hostel facilities’ SBS be mitigated through acceptable IEQ parameters of air temperature and relative humidity, increasing students’ wellbeing, academic performance, and reputation.

The work described in this paper has been performed to determine the potential use of meta-illite (KyAl4(Si8-y) O20(OH)4) calcined clay (MCC) as a supplementary cementitious material (SCM) in a binary Portland cement (PC) for high-performance concrete (HPC) production. To obtain the properties of the cementitious materials, the chemical composition, mineral phases, morphology, calcination efficiency and physical properties were quantitatively analysed using the advanced techniques of X-ray fluorescence (XRF), scanning electron microscopy/energy dispersive X-ray (SEM/EDX), X-ray diffraction (XRD), Fourier transform infrared/attenuated total reflection (FTIR/ATR), thermogravimetric analysis (TGA), laser particle sizing and Brunauer–Emmett–Teller (BET) nitrogen absorption method. The MCC’s effect on the workability and mechanical properties (compressive, splitting tensile and flexural strengths) and microstructure (morphology and crystalline phases) of hardened MCC-based HPCs were determined. The XRF result shows that the oxide composition of MCC confirmed the pozzolanic material requirements with recorded high useful oxides content. At the same time, the SEM image presents particles of broad, solid masses with a wider surface area of irregular shape. The XRD results show that the MCC was majorly an illite-based clay mineral calcined at a maximum temperature of 650 °C, as revealed by the TGA. The MCC addition increases the slump flow of HPCs at 5–15% cement replacement. The MCC incorporation at 10% cement replacement best improved the porosity of HPCs at a later age resulting in increased mechanical and microstructural properties of tested samples. Therefore, it is recommended that MCC addition within 10% cement replacement be adopted for low W/B Class I HPC at no deleterious results on mechanical and microstructural properties of the concrete.

Detailed geological mapping, petrographic description, and geochemical analysis were carried out to delineate variations in the rock types and their relationship with soil compositions in Dorowa, Barkin Ladi Local Government Area of Plateau State, Nigeria. The common rock types include hornblende-biotite-granite, biotite granite (medium to fine-grained), and pyroxene granite. The essential minerals identified by petrographic studies are quartz, plagioclase, biotite, hornblende, and pyroxene while zircon, magnetite, and ilmenite form part of the accessory minerals. The relative concentrations of heavy metals analyzed in the soils are in the order Fe > Cr > Ni > Pb > Cu > Zn > Br. The results show that soils near mineralized areas have anomalous concentrations of heavy metals. The implication of this is the increase of bio-availability and toxicity, which may lead to serious health and environmental consequences.

This paper examines the effect of combined bamboo fibers and limestone powder used as filler material on the fresh, hardened and microstructural properties of self-compacting concrete (SCC). The bamboo fibers of aspect ratio (l/d) of 50 and a maximum length of 50 mm was varied in steps of 0.25%, 0.5%, 0.75% and 1% in the SCC mix. While 10% of limestone powder was added as a filler in each of the SCC mix. The workability of the mix was assessed by slump flow test and V-funnel test, while the mechanical properties were assessed by considering the compressive and split tensile strength test after 7, 14 and 28 curing age. All concrete mixes were carried out by following the European Federation for Specialist Construction Chemicals and Concrete (EFNARC) standard, while the microstructure of selected samples was assessed using the Scanning Electron Microscopy (SEM). Test results indicate that fiber addition influences the fresh properties of SCC. Moreover, it was observed that SCC mix containing with fiber content of 0.75% and 0.5% with the inclusion of 10% limestone powder achieved the highest compressive and split tensile strength values of 28.04 MPa and 3.26 MPa, respectively. The result showed an increment of 17.4% and 32% compare to the control mix. Results of SEM showed an improvement in the morphology of the concrete. Hence, bamboo fiber and limestone powder can be sustainably combined to regulate the flow-ability and improving the strength of the self-compacting concrete for local structural construction.

•Concrete production process is usually designed to meet certain fresh properties, target strength and durability requirement. This process is referred to as the mix design, which guides the quantity and proportions of the various constituent materials to produce the concrete. Concrete mix designs are usually done in accordance to specified standard procedures in codes developed by recognized institutions like the Building Research Establishments (BRE) [1]. Other acceptable mix design methods includes the three (3) equation and double coating methods in [[2], [3]]. Standardized prescribed mix designs are generally accepted designs that meet strength requirements in normal strength concrete class as specified in [[4], [5]]. Standardized Prescribed Concrete mixes have been designed and the characteristic strengths specified in the British standards [[4], [5]] and the specified concrete mix design is recommended to be batched by weight.•Predominantly, mix designs are batched by volume within the study area and most developing countries which results to the production of less durable concrete than when batched by weight. This practice is due to the higher cost of acquiring the batching plants [6] employed in concrete production by medium to small scale construction firms.•This study developed a method of deriving a mix design to be batched by volume from the specified mix designed by weight using a design chat developed from [[4], [5]]. Concrete can then be produced with the derived mixed design and batched by volume as though it was batched by weight from the specified mix design. This method eliminates the strength disparity by both batching methods and production of more durable concrete in most developing countries.

Due to the increasing need for sustainability, the need for a cleaner environment and resources conservation has now become very important. This study investigates the possible utilization of waste glass powder combined with pulverized fired clay brick wastes as a partial replacement for Portland cement in the production of mortar. The fired clay bricks and glasses were sourced as waste materials and then crushed into powder form. It is then combined and used to partially substitute Portland cement in the mortar at replacement levels of 0, 5, 10, 20, 25, 30, 40 and 50% using a mix ratio of 1:2.75 at 0.5 water-binder ratios. Physical, chemical and morphological characterization was carried out on the pulverized materials. Further, the compressive strength test was carried out on casted 100 mm cube samples after curing by immersion in water. Obtained results revealed the pozzolanic reactivity potential of the blended waste glass and fired clay brick powder due to their amorphousness and high silica content, while also exhibiting similar oxides compositions. Moreover, the obtained compressive strength results of the blended mortar depict improved strength especially at an optimum value of 15% cement substitute with the blended fired clay brick and glass powder compare to the control. It is therefore suggested that blended mix of waste glass and fired clay brick powder with cement can be used in mortar component instead of open disposal in a landfill.

Utilization of secondary aluminium dross (SAD) as a constituent material in production of concrete is one of the recycling and value-added alternatives of reusing the waste due to the environmental friendliness, economy and improved performances associated with the material. This present study investigates the feasibility of incorporating SAD as a replacement binder in normal strength concrete (NSC). X-ray fluorescence (XRF) analysis revealed that the investigated SAD is rich in alumina content while exhibiting expansive property when tested via Le Chatelier apparatus. The studied fresh concrete samples blended with SAD recorded low workability and densities as the replacement levels increase. Compressive, split tensile and flexural strength tests conducted on the hardened concrete indicated a reduce strength as the percentage contents of the SAD increases when compared with the reference mixture. Moreover, the water absorption results also revealed higher water absorption capacity of the hardened concrete samples with increasing percentage contents of the SAD in the concrete samples. It is, therefore, suggested that blend of Portland cement (PC) with SAD content within 10% will be beneficial in the production of normal strength concrete for the structural purpose by the construction industry, while also limiting the impact of the aluminium waste on the environment.

Concrete of strengths classes ≥ C55/67 referred to as high strength or high-performance concrete (HSC/HPC) are noted to be generally of low water/binder (W/B), made from binary or ternary cements with silica fume (SF) being a necessary constituent, and often requiring internal curing. Non-availability and high cost of SF in most sub-Saharan Africa like Nigeria however makes HSC/HPC production in this region very difficult and hence the continued search for alternative supplementary cementitious materials (SCM) with good performance properties as constituents of ternary/binary cements in HPC. This study thereby examines the strength properties of metastable calcined clay (MCC) based HPC cured internally with superabsorbent polymer (SAP) 0.2–0.3% (by weight of binder (bwob)). HPC mixtures of varied MCC and Rice husk ash (RHA) contents containing two SAP grain sizes labelled (SP1 ˂ 300 µm and SP2 ˂ 600 µm) were cast in 100 mm cubes and cured for varying ages (7, 14, 28 and 56 days) before testing. The hardened specimens were subjected to compressive strength and water absorption tests at the varied curing ages for the performance assessment of the binder types and SAP grain sizes in HPC with age. This study revealed the possibility of achieving Class 1 HPC (50–75 N/mm2) utilizing industry manufactured calcined clay and locally produced RHA in Nigeria. The compressive strength of HPCs increased as the curing age increases for both SCM type, SAP contents and grain sizes. RHA based HPCs however showed better strength performance at the early ages than the MCC based. SAP addition in MCC based HPCs led to slight decrease in compressive strength as the SAP contents increased while the RHA based HPCs on the other hand, revealed slight increase in compressive strength with increase in SAP contents.