Nowadays, the significant demand for concrete has become a problem in concrete using aggregate from waste. Using standard concrete is recommended to reduce the breakdown of buildings. Unfortunately, standard materials used to produce previous concrete are not entirely environmentally friendly. As a result, many researchers have committed their awareness to identifying eco-friendlier substitutions in manufacturing concrete substitution aggregate from waste. In this respect, this paper discussed the proposed efficient procedure to indicate the compressive strength from mixed proportioning cockle shell, glass powder, and epoxy resin as concrete under hot water curing conditions (60°C, 4 hr) using response surface methodology. The experimental design used in this research uses a response surface methodology. There are three aggregates to be investigated, namely cockle shell powder, glass powder and epoxy resin under hot water curing condition (60°C, 4 hr). Under hot water curing conditions, this research discovered that adding 4.0% cockle shell powder and 10.0 % glass powder increased the compressive strength to 104.68 MPa. On the other hand, 4.0% cockle shell powder, 10.0% glass powder and 2% epoxy resin under hot water curing conditions improved the compressive strength to 115.70 MPa. It was therefore inferred that the use of both cockle shell powder and glass powder to produce cleaner and compressive strength concrete is applicable, both mechanically and environmentally.

The slenderness ratio, length to diameter, of the cylindrical concrete samples of the slab block by the core-drilling method is believed to affect the compressive strength other than the aggregates in the concrete. In this study, the relationship between the compressive strength with mixing and slenderness ratio of cylindrical concrete specimens was investigated by statistics. Further, the discrimination model for mixing cylindrical concrete specimens has been developed by using machine learning algorithms, including support vector machine (SVM), linear discriminant analysis (LDA), k-nearest neighbor (k-NN), and random forest (RF). A total of 180 cylindrical concrete specimens have been measured for compressive strength using UTM. The sample consisted of a mixture of type-A and type-B with a slenderness ratio of 2.48, 2.72, and 3.28, respectively. Samples were obtained by the core-drilling method from slab block concrete. The ANOVA tests showed that the aggregate and slenderness ratio caused a significant difference in the compressive strength of the concrete (p<0.05). This indicates that the type of aggregate mixture in concrete and the slenderness ratio of cylindrical concrete specimens significantly affect the compressive strength of the concrete. The model for discrimination of mixing cylindrical concrete specimens using machine learning algorithms can be used with satisfactory results. LDA is a machine learning algorithm that can show stability in the training and testing stages with accuracy reaching 78% and inconsistency of less than 2.63% (the smallest compared to others). The descending order of machine learning algorithms based on their consistency is LDA > RF > SVM > k-NN. Subsequently, this model can discriminate the aggregate mixture on cylindrical concrete specimens obtained from the core-drilling method.

Nowadays, with increased demand for aggregates for concrete and an awareness of the need of protecting natural resources, experts are becoming increasingly interested in waste material as a building material substitute. However, the compressive strength is influenced by the composition of concrete. In this study, the compressive strength of concrete under substitution using waste from cockle shells and glass was investigated using Response Surface Methodology (RSM). Central Composite Design (CCD) based on RSM was used to assess the influence of epoxy resin, cockle shells powder, and glass powder on compressive strength responses. RSM developed first-order and second-order mathematical models with findings from experimental design. Analysis of variance was used to determine the correctness of CCD's mathematical models. Desirability analysis was then employed to optimize epoxy resin, cockle shells powder, and glass powder yielding maximum compressive strength. The RSM analysis revealed that the empirical results fit well into linear and quadratic models of concrete compressive strength. The mixing components will produce cement with compressive strength in each formulation of 54.71 MPa (4.88% epoxy resin and 4.0% cockle shells powder), 47.82 MPa (6.85% epoxy resin and 8.0% glass powder), 147.0 MPa, (4% cockle shells powder and 8% glass powder), and 56.08 MPa (4.4% epoxy resin, 4.0% cockle shells powder, and 8.0% glass powder). The results confirmed that a reasonable compressive strength of concrete could be achieved using epoxy resin, cockle shells powder, and glass powder.

Domestic cement demand is increasing in line with the increase of development of property sector and construction sector. Cement is one of the important components in making a permanent building. The function of cement in a construction is as an adhesive material that affects the strength of a building. The process of making cement is divided into two groups, namely hydraulic cement and non-hydraulic cement. Hydraulic cement consists of Portland type cement and PCC type cement, PPC cement and slag cement. The type of PCC cement (Portland Composite Cement) is produced from grinding clinker with gypsum with the addition of third raw material. The purpose of this research is to know the effect of cement quality improvement with substitution of basalt scoria stone raw material as much as 0-10% as the third raw material. The source of basalt scoria stone originated from Lampung Timur, Indonesia. The fineness test showed cement fineness was 2983-3665 cm2/gr with minimum SNI standard 2800 cm2/gr. Residue test meets the requirements of SNI standard that is equal to 16,07% -18,55%. The compressive strength test was performed at ages 3, 7 and 28 days and obtained the result that the optimum compressive strength produced was 235, 314, 394 kg/cm2. Basalt rock usage as substitution material in cement production can decrease environmental pollution caused by clinker production. Based on the cost estimation analysis, the use of basalt stone can decrease the production cost which impact on the increase of profit

The proportions of the concrete are critical for obtaining a high-strength, high-quality product. Different concrete grades may support varying loads and have varying ratios. Therefore, the objectivity of this research is to study mechanical performance from concrete treated with iron sand, glass powder, and hot water curing. The level of iron sand and glass powder treatment added to the SNI concrete composition is 2% to 10%, 1% to 5%, (w/w), respectively. The curing time and temperature were applied between 1 hr to 4 hr and 301 K to 343 K. The compressive strength of the concrete was tested on 0, 1, 3, 7, and 28 days after molding using UTM with a combination of linear regression and response surface models for optimization. The addition of iron sand and glass powder to increase the best compressive strength was 10%, 2.45%, respectively. Iron sand treatment of 10% combined with glass powder filler 3.04% was predicted to give the best compressive strength of 32.50 MPa. The compressive strength value of this treatment was 21.78% higher than that of SNI concrete. Treat the curing temperature, curing time, and age of the concrete which gives the best compressive strength (28.33 MPa) with SNI concrete composition of 301 K, 4 days, and 28 days. This research shows that the addition of iron sand, glass powder, and hot water curing to the composition of SNI concrete can increase its compressive strength.