Abstract:
This study is aimed to develop concrete blocks made from using the mixtures of calcium carbide
residue-fly ash (CR-FM) and calcium carbide residue-bagasse ash (CR-BA) as a binder without
Portland cement. The ratio of calcium carbide residue (CR) to fly ash (FM) and calcium carbide
residue to bagasse ash (BA) were 30:70 and 5050 by weight, respectively. Fine recycled concrete
aggregate was also used to 100% replace river sand and crushed limestone dust. The binder to
aggregate ratio was kept constant at 1:3 by weight. In this research, all concrete blocks were divided
into four groups. The first group was the concrete blocks made from using original calcium carbide
residue-fly ash as a binder with the water to binder ratios of 0.45, 0.40, and 0.35, and the concrete
block mixtures were cast by using a pressure of 60 kg/cm the powerof 2. The second group was the concrete
blocks made from using ground calcium carbide residue-fly ash as a binder with the water to binder
ratios of 0.40, 0.35, and 0.30, and the concrete block mixtures were cast by using a pressure of 60
kg/cm the powerof 2 The third group was the concrete blocks made from using ground calcium carbide residuefly
ash as a binder with the water to binder ratios of 0.40, 0.35, and 0.30, and the concrete block
mixtures were cast by using a pressure of 80 kg/cm the power of 2. The fourth group was the concrete blocks made
from using ground calcium carbide residue-bagasse ash as a binder with the water to binder ratios of
0.50, 0.45, and 0.40, and the concrete block mixtures were cast by using a pressure of 60 kg/cm the power of 2.
The concrete block specimens having a cross-section of 10x10 cmthe power of 2 and a length of 20 cm were used
in this study. The effects of water to binder ratios, compaction pressures, and fineness of binder on
the compressive strength, flexural strength, abrasion resistance, and water absorption of concrete
blocks were investigated.
The results showed that the compressive strength of concrete blocks made from ground calcium
carbide residue-fly ash was 414 kg/cm the power of2 at 28 days and developed as high as 453 kg/cm the power of 2 at 60 days.
According to the Thailand Industrial Standard (TIS 827), it could be categorized as a paving
concrete block. The concrete blocks made from the mixture of ground calcium carbide residuebagasse
ash gave the compressive strengths of 274 and 306 kg/cmthe power of 2 at 28 and 60 days, respectively.
Consequently, it could be categorized as a bearing block according to the Thailand Industrial
Standard (TIS 59). The water absorption of the concrete blocks made from both calcium carbide
residue-fly ash (CR-FM) and calcium carbide residue-bagasse ash (CR-BA) and containing fine
recycled concrete aggregate decreased with the increase of density, which were approximately 7 to
13% by weight.
The results showed that flexural strength of the concrete blocks made from both calcium carbide
residue-fly ash (CR-FM) and calcium carbide residue-bagasse ash (CR-BA) with recycled fine
concrete aggregate increased with the increase of compressive strength and curing age. The flexural
strength of concrete blocks was about 11 to 20% of its compressive strength. Finally, the weight loss
of concrete blocks due to abrasion decreased with the increase of compressive strength, and was
about 1.75 to 10.90 grams at abrasion time of 12 minutes.
The results also suggested that the waste materials such as calcium carbide residue, fly ash, and fine
recycled concrete aggregate could be used as raw materials to make concrete blocks without
Portland cement and the properties of concrete block met the requirement specified by TIS 827
standard, which states that the compressive strength of the block be higher than 400 kg/cm the power of 2.